TB sync.

[kruuuzn]

I just purchased a Morgan Carbtune. Can somebody point me in the direction of a good step by step tutorial on the proper way to sync the throttle bodies on my R1150RT?

 

Thanks!

[AndyS]

 

[dirtrider]

11 minutes ago, kruuuzn said:

I just purchased a Morgan Carbtune. Can somebody point me in the direction of a good step by step tutorial on the proper way to sync the throttle bodies on my R1150RT?

 

Thanks!

 

Afternoon  kruuuzn

 

Have you removed & cleaned the BBS screws & the air passages under  them? If not then this is the first step.

 

You should also adjust the valves before doing a TB sync,  have you done that yet? Valve adjustment can effect the engine vacuum therefore effect the TB balance. 

[AndyS]

https://ibmwr.org/original/r-tech/oilheads/R11Manual/Oilhead_Maintenance_2-25-02.pdf

 

There is a whole world of resources out there to help you get your bike in tip top form.

 

Remember though, there is a sequence such that you need everything else to be right before the throttle body synch.

So, Air filter (clean or replace). Spark plugs clean (but ideally replace to establish a good baseline). Oil and filter change (for no other reason that it is good to know you have nice clean oil)! 

As DR says, get the valves sorted before the TB synch. What mileage have you got on your bike?

[dirtrider]

Afternoon  kruuuzn

 

Some of the  IBMWR procedures in the link that Andy posted  were written long ago and do contain some errors (since proven out to be incorrect), some just minor & some more blatant.

 

The basic procedures are a decent how-to guide but keep in mind that not all the info is accurate or correct (especially the 1100 single cable system adjustments & the Lentini TPS adjustments. Possibly more as I haven't completely read though those  IBMWR procedures in a long time now.

[roger 04 rt]

Here is an annotated BMW TB sync procedure. It also contains an emergency z=250 outline. 

 

https://www.bmwsporttouring.com/topic/77572-tps-alignment-idle-speed-adjustment-beyond-zerozero/page/2/?tab=comments#comment-925217

 

[kruuuzn]

Thanks gang.

 

32,600 miles. 2004 purchased new.

 

Yup, after deciding to finally do all the maintenance myself I have changed the oil and filter (always have done this myself), air filter, tranny fluid, final drive fluid, new spark plugs, adjusted the valves, new alternator belt, and new fuel filter. I actually replaced the fuel pump and ALL the rubber tubing in the tank. I figured there's not a lot of miles on the bike but all these components have been sitting in gas for FIFTEEN years. LOL

 

Although, I think I'll still ride the 150 miles to the dealer in Grand Rapids to have them flush the brake and clutch fluid along with new pads. I don't feel like messing with the ABS system. I've seen it give THEM grief in the past.

 

I just finished wiring an Eastern Beaver 3-circuit to power new Clearwater lights and SW-Motech electrified tank bag. I'm happy with those results.

 

Is there anything else I should be addressing?

[kruuuzn]

1 hour ago, dirtrider said:

Have you removed & cleaned the BBS screws & the air passages under  them? If not then this is the first step.

 

Is that the brass screw on the TBs? What is the procedure for that?

 

What does BBS stand for?

[dirtrider]

40 minutes ago, kruuuzn said:

 

Is that the brass screw on the TBs? What is the procedure for that?

 

What does BBS stand for?

 

Afternoon  kruuuzn

 

Yes BBS (Big Brass Screws) are the air by-pass screws on the throttle bodies.

 

To clean the BBS & passages under them, first turn each side BBS all the way in until seated (count the number of turns & partial turns to seat each side screw then write that down), then remove the screws on each TB & clean the screws & screw tips of the black coking using spray  carburetor cleaner.

 

Next, use an o2 sensor safe carburetor cleaner spray & clean the air passages that are under the screws (caution: don't get the carb clean on any painted surfaces including the frame). I usually remove the vacuum hoses (or vacuum caps) from the bottom of the throttle bodies  then attach drain hoses to help guide the excess carb clean & black goo away from the motorcycle  (some of the old 1150 bikes will have a lot of BBS air passage coking).

 

Then reinstall the  BBS screws (on the very same side that they came out of), then turn in until lightly seated, then back out the same number of turns & partial turns that you wrote down in step one.

 

The nominal adjustment on those BBS screws is about 1-1/2 turns out from seated so if yours are way different than that then  possibly someone in the past has adjusted them with dirty screws & dirty air passages. (if in doubt & IF you are going to balance the TB's then you can just start with each side BBS at 1-1/2 turns out from lightly seated.  

 

  

[kruuuzn]

"Big brass screw". haha........go figure.

 

Okay, got it.

 

What is the function of these screws? Did I read somewhere they're for idle adjustment?

 

Also, I'm assuming it would NOT be a good idea to use air pressure to help clean the air passages? Just let gravity do it's job?

[dirtrider]

39 minutes ago, kruuuzn said:

"Big brass screw". haha........go figure.

 

Okay, got it.

 

What is the function of these screws? Did I read somewhere they're for idle adjustment?

 

Also, I'm assuming it would NOT be a good idea to use air pressure to help clean the air passages? Just let gravity do it's job?

 

Afternoon  kruuuzn

 

On the BMW fuel injected boxer bikes the throttle plates close down on  fixed (basically non adjustable) stop screws as the L/H TB has a TPS (Throttle Position Sensor) that needs to return to a fixed & set location.

 

So the throttle bodies have those BBS screws that are basically air by-pass screws.   They set the amount of intake air that flows around (by-passes) the closed throttle plate. The more open the BBS, then more air can flow around the throttle plate, so the engine then idles faster.

 

The air by-pass is limited as the fueling computer needs to add more fuel as the amount of by-pass air is increased.  

 

Yes, those BBS screws are basically for base idle RPM adjustment. But you sort of need to keep the by-pass air flow even side to side so the BBS are basically adjusted for BOTH hot cub idle RPM but also adjusted using a vacuum gauge of some sort or other to keep the vacuum even side to side at curb idle.  

 

You can use very light  air pressure to clean those BBS air passages but the TB is captured on the rear with the air box & on the front with the cylinder head so the crap that you blow around with compressed air migrates to places it shouldn't. Those BBS air passages are very short (directly from the BBS screw cavity to the just in front of the throttle plate so they do clean pretty easily with just a blast of o2 safe carb cleaner.   

[dirtrider]

Afternoon  kruuuzn

 

Maybe just a little more on the Throttle Body balance thing (basically a cross side balance)

 

It is basically a very simple procedure & simple requirement complicated by all the big words & mystery.

 

You use the BBS screw adjustment to set the curb idle cross side vacuum to be equal  (throttle plates closed on the base idle stop screws) (this is very simple), BUT, the added difficulty is in trying to keep the idle vacuum equal side to side using the BBS screws without getting the curb idle RPM too high or too low. Once you get the cross side idle vacuum equal you can then increase or decrease the idle RPM by turning both side BBS in or out the same amount. Actually very simple  but can be kind of fiddly until you get the procedure learned.  

 

The other part of the TB balance is again getting the vacuum even on both sides but this time doing it with the engine RPM higher & with the throttle plates held open with the twist grip  (for this you  adjust the throttle cables going into the throttle bodies (this is also a very simple procedure but it can be intimidating until you do a few & understand the process.

 

Probably the biggest problem that I see with first time TB balance attempts is in not understanding the cause of higher or lower vacuum readings. Most  equate a more open throttle plate to higher engine vacuum this is NOT the case & is confusing to many. This leads to moving the cable adjuster the wrong direction to begin with then it snowballs from there & gets more difficult to recover & get it straightened out.    

 

In measuring the engine vacuum at the TB nipples you are measuring the pressure drop across the throttle plate so the more OPEN the throttle plate the LOWER the vacuum (pressure drop) is. Remember that you are measuring the lack of pressure (ie vacuum) on engine side of the throttle plate so the more that you open the throttle plate the more atmospheric pressure you are allowing in so the less the pressure drop across the throttle plate.  

 

Or an easy way to think of it is: with throttle plate completely closed you have the highest negative pressure  (highest vacuum)  reading, as you open the throttle plate you are allowing more (atmospheric) pressure in therefore raising the negative pressure   reading towards 0.    

 

Closed throttle plate = higher vacuum reading

Open throttle plate =    lower vacuum reading

 

A simple trick that I use is to simply reach in with a finger & push on a throttle cable slightly  while watching the vacuum gauge (or vacuum measuring device). That pushing on the throttle cable opens that side throttle plate slightly more. So if a slight push on the throttle cable moves your vacuum meter in the correct direction then you instantly know that side throttle cable needs to be shortened (cable housing lengthened) to open the throttle plate slightly more.

 

 If a slight push on the throttle cable moves your vacuum meter in the wrong direction then you instantly know that side throttle cable needs to be lengthened  (cable housing shortened) to open the throttle plate slightly less.    

[kruuuzn]

Thanks for the explanations DR. I think the concept is beginning to sink in. 

 

I bought some carb cleaner tonight, pulled the brass screws, and cleaned everything like you recommended. The ends of the screws were fairly clean and I was surprised to learn the screws were only 3/4 of a turn from full stop.

 

I’ve got my gas tank back together with all the new components and everything seems to be working correctly (low fuel warning light AND fuel gage). I’ll buy some fresh gas tomorrow night and start playing with my new Carbtune toy.

 

On syncing the high rpm, do you know if my bike requires adjusting both throttle cables or just the right side?

 

Thanks again.

 

 

[dirtrider]

9 hours ago, kruuuzn said:

Thanks for the explanations DR. I think the concept is beginning to sink in. 

 

I bought some carb cleaner tonight, pulled the brass screws, and cleaned everything like you recommended. The ends of the screws were fairly clean and I was surprised to learn the screws were only 3/4 of a turn from full stop.

 

I’ve got my gas tank back together with all the new components and everything seems to be working correctly (low fuel warning light AND fuel gage). I’ll buy some fresh gas tomorrow night and start playing with my new Carbtune toy.

 

On syncing the high rpm, do you know if my bike requires adjusting both throttle cables or just the right side?

 

Thanks again.

 

 

 

 

Morning  kruuuzn

 

No way to know that until you  start the procedure. If both side cables have some slack & the initial balance check shows both sides are close on balance then you can probably just adjust the R/H side. If one side cable is tight & the other is loose and/or the balance is way then off then you will probably have to adjust both sides.

 

[kruuuzn]

Gotcha.

So my bike has a Y-cable running to both TBs correct?

It seems like I read somewhere that the left TB is controlled by the right TB adjustment, or something weird like that. That must have been a different bike.

What does the high idle cable control?

[dirtrider]

32 minutes ago, kruuuzn said:

Gotcha.

So my bike has a Y-cable running to both TBs correct?

It seems like I read somewhere that the right TB is controlled by the left TB adjustment. That must have been a different bike.

What does the high idle cable control?

 

 

Morning  kruuuzn

 

This brings us back to the BMW 1100/1150 thing. While the BMW 1100 & 1150 are similar they CAN BE vastly different in certain areas. So be very careful in what you read to be sure that it applies to YOUR  particular year & model 1150 motorcycle.

 

The early BMW 1100 bikes used a single throttle cable that first ran to the L/H TB then kept going on to the R/H  TB.  On those the L/H adjustment can effect the R/H adjustment.

 

Your later 1150 bike has a single cable running to a Bowden box (splitter box) then from there a short (individual) cable runs independently to each TB  (it's this short independent cable that gets adjusted for TB balance)

 

What does the high idle cable control? --It basically controls a wedge like deal inside the Bowden box that forces the cable cam to advance & hold the TB's (throttle plates) open slightly.  

 

Added: Bowden box picture__

 

[roger 04 rt]

Morning DR,

 

Nice explanations, as usual, of all the moving parts. If one follows the procedure and re-tentions all the cables before making the final left-right adjustments between 1100 and 2500 RPM, it seems to that you’re better off adjusting the right hand screw if the left side has the higher vacuum but the left side screw if the right side has higher vacuum. That way you are always slightly loosening an adjuster.

 

RB

[kruuuzn]

Excellent. Thank guys. That really clears it up.

 

Should you start by adding a little cable free play at the handle bars and then adjust it out when the sync is complete?

[dirtrider]

21 minutes ago, roger 04 rt said:

Morning DR,

 

Nice explanations, as usual, of all the moving parts. If one follows the procedure and re-tentions all the cables before making the final left-right adjustments between 1100 and 2500 RPM, it seems to that you’re better off adjusting the right hand screw if the left side has the higher vacuum but the left side screw if the right side has higher vacuum. That way you are always slightly loosening an adjuster.

 

RB

 

 

Morning Roger / kruuuzn

 

This is good advise for a minor balance tweak as it prevents overly tight cables  but if the cables are not 'properly' re-tensioned before the TB balance  (something most shops and/or home tuners don't do, or don't do correctly) then you can end up with some extra cable slack in the short cables.

 

This extra slack makes getting enough fast idle from the choke (fast idle) lever almost impossible. 

 

The lack of enough fast idle (even with a fast idle full cable adjustment) is a somewhat common complaint on the BMW 1150 bikes more than likely due to a life of improper short cable adjustments.

[dirtrider]

15 minutes ago, kruuuzn said:

Excellent. Thank guys. That really clears it up.

 

Should you start by adding a little cable free play at the handle bars and then adjust it out when the sync is complete?

 

 

Morning  kruuuzn

 

Yes, I usually do as that eliminates a tight upper cable from preventing one or both of the TB throttle plate levers from FULLY contacting the throttle stop screws.

 

My suggestion is to first loosen the upper cable a little to prevent that from interfering with your TB balance.

 

Then see if you NOW have enough fast idle RPM. --if OK so far then just lightly tweak the short cable adjusters to get a balance (if just a little tweak needed then do as Roger posted above). If more than slight adjustment needed then split the difference (if a full turn short cable adjustment is needed  to get a balance then get 1/2 from one side & the other 1/2 from the other  side. If in doing this you start to get a tight short cable DO NOT tighten that side any further, back it off slightly then move to the other side & get your balance adjustment there.

 

Or better yet (if you have the time, energy, & knowledge) then refer to Rogers  way above post & start with a full cable re-tension. 

[kruuuzn]

I would think you should add some slack in both the upper throttle cable AND fast-idle cable, complete both sync operations, then come back and adjust the slack out of the cables. Is that not correct?

[dirtrider]

9 minutes ago, kruuuzn said:

I would think you should add some slack in both the upper throttle cable AND fast-idle cable, complete both sync operations, then come back and adjust the slack out of the cables. Is that not correct?

 

Morning  kruuuzn

 

Yes to the upper cable, maybe on the fast idle cable. Just find the adjuster on the fast idle cable, then slide the rubber boot down the cable.   Then lightly pull the fast idle cable apart at the adjuster (you should have a lot of pull-apart there (slack), if so then no need to back the fast idle cable adjuster off.

 

The fast idle wedge in the bowden box is spring loaded so IF there is slack in the fast idle cable then the  spring should have pulled the wedge back from interfering with the balance.

 

If you want to add another project to your already full plate then seeing as you already have the fuel tank removed you can slide the bowden box out (not real easy to do)  then flush it out & blow it out with compressed air (over the years those Bowden boxes do get curded up inside, especially if the cable was over-lubricated) 

[kruuuzn]

Thanks. Everything makes sense now.

Realizing the existence of the Bowden box and how it operates helps tremendously.

I should be able to reason my way through this now.

[kruuuzn]

Then lightly pull the fast idle cable apart at the adjuster (you should have a lot of pull-apart there (slack), if so then no need to back the fast idle cable adjuster off.

 

But then again, this is a little fussy. There "should" be slack in the fast idle cable?

[dirtrider]

1 minute ago, kruuuzn said:

Then lightly pull the fast idle cable apart at the adjuster (you should have a lot of pull-apart there (slack), if so then no need to back the fast idle cable adjuster off.

 

But then again, this is a little fussy. There "should" be slack in the fast idle cable?

 

Morning  kruuuzn

 

Yes, that cable usually still has slack even when fast idle adjusted properly (your fast idle lever is basically a 3 position deal.

 

With off being one of the positions, next is the center lever position (it should lock or stay  there for moderate fast idle ) with no cable slack in this position, then the 3rd position is lever manually held all the way up for cold starting & initial very fast idle (there is lot of spring tension in this position & no cable slack).   

[kruuuzn]

Gotcha.

[kruuuzn]

How many cmHg's will my RT pull?

I'm reading the directions on the Carbtune and if the cmHg's are under 8 you need to turn it upside down.

[dirtrider]

2 hours ago, kruuuzn said:

How many cmHg's will my RT pull?

I'm reading the directions on the Carbtune and if the cmHg's are under 8 you need to turn it upside down.

 

Afternoon kruuuzn

 

I really don't know as haven't had an inches of mercury vacuum gauge on a BMW boxer in years now (I would guess)  around 16" of  Hg (40.5 CM Hg) at idle & slightly less at no-load 2500-3500 RPM's.

 

The BMW boxer is kind of a unique engine configuration  in that one side cylinder opposes the other so that type of intake lends itself to a much more accurate cross-side balance using a simple "U" tube liquid manometer & measuring in inches of H2o.

 

Devices like the carb tune usually measure inches of mercury (Hg)  or CM's of mercury vacuum  against ambient atmospheric  pressure. 

 

1" Hg equals about 13.5" H2o  & I usually balance to well under 3" H2o so you can visualize the difference in resolution.      2" of H2o isn't even a needle wiggle on an Hg vacuum gauge.

 

Devices like the carb tune are quick & easy to use but pre-check verification of meter calibration between sides is critical as well as the cross side resolution isn't usually as good as a  simple homemade liquid manometer. (carb tune does work better on multi cylinder non boxer engines as those will not work well with a "U" tube type manometer unless the  column tubes are 20 feet tall).

 

With "U" tube liquid manometer all you need to do is adjust the TB balance until you get equal height water columns (it really is that easy). The downside of using a liquid manometer is the TB balance needs to be fairly close to begin with or the high vacuum side will suck the liquid out of the "U" tube. The longer the liquid tube length (tube height) the farther the balance can be off before it can suck the liquid out.

On my personal "U" tube manometer I have 'both' catch containers on each side hose (catches any liquid that gets sucked out from a way-off initial balance, or an incorrect cable adjustment, and a small aquarium bubbler valve on each side hose as that allows the valves to be opened very slowly & in very slight increments until I determine that the initial balance is close enough to not suck the liquid out.

 

The liquid manometer that  I have in my shop   has 10' column height hoses so that can be used even on most way-out-of-adjustment TB's.     

 

If you have a carb tune then you might do the initial TB sync with the carb tune, then if you have the time use a simple "U" tube liquid manometer to do a final re-check and if found slightly off then use the "U" tube to tweak it & get it perfect.     

 

 

   

[kruuuzn]

Bummer. I guess I should have asked some opinions before buying the Carbtune.

[dirtrider]

9 minutes ago, kruuuzn said:

Bummer. I guess I should have asked some opinions before buying the Carbtune.

 

Afternoon kruuuzn

 

Can you send it back?  If not then it is handy to have around as it will work  OK for adjusting (especially for initial adjustments on a BMW that you are not sure is even close to begin with). Like after all throttle cables replacement or major TB work.

 

The carb tune is a better device to use on a multi cylinder (non opposed) engines as those usually need to be adjusted against atmospheric pressure.

 

The BMW 2 cylinder boxer is just one of those outlier engines that responds very nicely & accurately to a simple "U" tube manometer.  

[AndyS]

19 minutes ago, kruuuzn said:

Bummer. I guess I should have asked some opinions before buying the Carbtune.

 

Can we clarify which carbtune you have. Mine is a mercury manometer and is wonderfully reliable and easy to use.

[kruuuzn]

This one has the stainless steel slugs that float in the tubes.

[Jim Moore]

Brother, I think you're getting a little wrapped around the axle on this. Generally there is no need to loosen any cables before you start. Cables never tighten up. They always stretch. If anything there's already too much slack. Check to see if the set screws are resting on the stops. Youi can check them visually or by rolling the throttle on and off and listening for them to bottom out. If they are, you're good to go.

 

Warm the bike up, then shut it down and attach the Carbtune. Work on one side or the other, Most people use the right side. Play with the BBSs. See the effect on the carbtune. Even out the columns, then check your idle rpm. The spec is 1000-1100, but I like 1200-1300. It seems to come off the bottom a little more crisply. YOu may have to adjust both sides to get that number.

 

Then roll the throttle up and down a little bit. I like to shoot for 1800-2000 rpm. If the columns aren't even undo the locknut and adjustments using the knurled adjuster. Right raises, left lowers. Make small adjustments. An eighth of a turn is a lot. Also, tightening the adjuster will change the columns, so I follow this (probably overly complex) procedure. Start bike>Check balance>Shut bike down>Loosen locknut>Adjust knurled adjuster>Tighten locknut>Start bike>Check balance again. A few iterations of that is all it usually takes. Note that you have to hold the adjuster still with a pair of needlenosed pliers while you loosen and tighten the locknuts.

 

Btw, is your fast idle cable functioning? If not, it's probably not the cable. Rather, it's the lower cables. They become stretched over time. Eventually the fast idle only takes up the slack in the cables instead of opening the butterflies. In that case you need to take almost all the slack out of the left side, then do the same to the right side, then make your synch adjustments.

[kruuuzn]

7 hours ago, Jim Moore said:

Brother, I think you're getting a little wrapped around the axle on this.

 

Ouch! I HATE when that happens! Hahaha

Ya, I’m sure I’m reading WAY too much into this. It’s one of my many character flaws! 

 

And yup, my fast idle works correctly.

 

DR, Mike at Beemer Boneyard was gracious enough to allow me to return the Carbtune. So I guess I’ll be in Home Depot at 6:00 in the morning buying a bunch of 3/16” ID tubing.

[dirtrider]

9 hours ago, kruuuzn said:

 

Ouch! I HATE when that happens! Hahaha

Ya, I’m sure I’m reading WAY too much into this. It’s one of my many character flaws! 

 

And yup, my fast idle works correctly.

 

DR, Mike at Beemer Boneyard was gracious enough to allow me to return the Carbtune. So I guess I’ll be in Home Depot at 6:00 in the morning buying a bunch of 3/16” ID tubing.

 

Morning kruuuzn   

 

3/16" tubing is perfect for the lines going from the "U" to the TB nipples but is a bit on the small side for the  "U" part. 3/16" will work but that smaller diameter will allow a lot of fluid stiction of the fluid to the tubing walls (especially if you put some antifreeze in the water to give it color & prevent freezing, or switch the fluid to light 2cycle oil).

 

1/4" or even 5/16" usually works better for the "U" part but not absolutely needed.  

 

 I usually clamp the lines off (brake hose clamps, or aquarium bubbler valves, or even needle nose pliers with zip ties across the handles) until the engine is started & smoothly idling as that prevents a ragged startup from sucking the fluid out of the  "U".

 

You can also use the clamps or valves to reduce the fluid bounce in the "U" tube by adding some restriction. I usually turn my aquarium bubbler valves down until the fluid bouncing stops but the fluid height responds quickly to any adjustments (a very slight push on the throttle cable at a TB  to slightly open a throttle valve (very very slight)  will confirm that your fluid height in the "U" tube is responding.

[roger 04 rt]

22 hours ago, dirtrider said:

 

 

Morning Roger / kruuuzn

 

This is good advise for a minor balance tweak as it prevents overly tight cables  but if the cables are not 'properly' re-tensioned before the TB balance  (something most shops and/or home tuners don't do, or don't do correctly) then you can end up with some extra cable slack in the short cables.

 

This extra slack makes getting enough fast idle from the choke (fast idle) lever almost impossible. 

 

The lack of enough fast idle (even with a fast idle full cable adjustment) is a somewhat common complaint on the BMW 1150 bikes more than likely due to a life of improper short cable adjustments.

 

Morning DR,

I agree, properly retentioning the cables is an integral part of a good sync and for some it’s an extra step that seems unnecessary. Once that’s done I’ve then found that trying to reduce the vacuum on the right side by turning the adjuster out may over tighten that cable.

 

The Motronic is looking for a few degrees of throttle opening and I’ve found the best way to set it accurately is by measuring the TPS voltage with the Fast Idle Lever in the detent position midway. It can be a compromise to find the right setting but I like to have 1700-1800 RPM on a hot engine and adjust the fast idle cable until the TPS voltage is around 850 mV.

 

22 hours ago, kruuuzn said:

Then lightly pull the fast idle cable apart at the adjuster (you should have a lot of pull-apart there (slack), if so then no need to back the fast idle cable adjuster off.

 

But then again, this is a little fussy. There "should" be slack in the fast idle cable?

 

The process of a good TB sync is superficially getting the idle speed and balance right. On another level, the Motronic expects TPS, airflow, idle speed to be set precisely, to certain values so that idling, takeoff, small throttle performance and cold starting all work effectively.

 

In my experience you can’t be too fussy. You can take shortcuts and your bike will function, but not at its best.

[kruuuzn]

Oops, my post should have read: "this is a little FUZZY", ie I didn't quite understand. Sorry for the confusion.

 

Thanks for all your help gents. I think Einstein said "once you stop learning you start dying". I've learned a lot from you guys.

 

DR, I'll stop back at Home Depot and buy the next size tubing that will fit over the OD of what I already purchased. And since I'm also into fish keeping I've got several tubing valves laying around. Cant wait to give this a try.

 

 

[dirtrider]

15 minutes ago, kruuuzn said:

Oops, my post should have read: "this is a little FUZZY", ie I didn't quite understand. Sorry for the confusion.

 

Thanks for all your help gents. I think Einstein said "once you stop learning you start dying". I've learned a lot from you guys.

 

DR, I'll stop back at Home Depot and buy the next size tubing that will fit over the OD of what I already purchased. And since I'm also into fish keeping I've got several tubing valves laying around. Cant wait to give this a try.

 

 

 

Morning kruuuzn

 

It sure isn't rocket science but getting your first  manometer set up & doing what it needs to do is just a bit fiddly.

 

Just make sure that you engine is hot (hot oil & stable idle) before hooking up your manometer.

 

Once you figure it out (you have enough info in the above posts to do that)  then you will find it a great tool for very precision TB adjustments.

 

If you have removed your evap can & plugged the TB nipples then you might do as I used to do on the BMW 1100/1150 bikes that I owned. 

 

That is to buy a little extra tubbing then run it from each TB nipple to up under the seat then plug it off there. That way you can check the TB balance any time that  you like by just removing the seat & plugging in your manometer. Can't adjust the cables but you can check it to see  if you even need to remove the plastics.   

[kruuuzn]

Given the sensitivity of water, how close can I expect to make the two levels?

[dirtrider]

1 hour ago, kruuuzn said:

Given the sensitivity of water, how close can I expect to make the two levels?

 

Morning kruuuzn   

 

That depends, on some I can get them dead nuts even at idle (with slightly bouncing water columns) & at the above idle 2500ish I can usually get the water columns to work back & forth across the even point as I lightly  work the throttle twist grip.

 

You can usually get them even at some point in the throttle plate opening but then they will be slightly off at another opening & this can vary depending of if you are opening or closing the throttle.

 

I usually consider  anything under 3" of H2o WAY better than BMW specs.  If your bike has a lot of throttle shaft wear then maybe more variance as you work the throttle (but your low mileage should not have a lot of throttle shaft wear). --   3" H2o is about .22 " of Hg (not even a blip on most rod type or Hg based balancing devices)

 

Bottom line: best possible with reasonable effort/  

[kruuuzn]

I’ve got a question:

 

I’ve built my manometer and have started tuning.

Before I started this job the BBS were: LH 3/4 turn out and RH 5/8 turn out.

Now to get the fluid balanced and the correct idle the LH is 2-1/2 turns out and the RH is 1 turn out,

 

Does that make sense?

 

 

[dirtrider]

52 minutes ago, kruuuzn said:

I’ve got a question:

 

I’ve built my manometer and have started tuning.

Before I started this job the BBS were: LH 3/4 turn out and RH 5/8 turn out.

Now to get the fluid balanced and the correct idle the LH is 2-1/2 turns out and the RH is 1 turn out,

 

Does that make sense?

 

 

 

 

Evening kruuuzn

 

It can make sense as some can easily  be that much different. But,  2-1/2 turns vs 1 turn out is  just enough difference to verify no vacuum leaks. 

 

So,  you still might  want to verify all the possibilities that could effect it.

 

So first thing make darn sure that there are no intake leaks on the cylinder head side of the TB's.  (like loose clamps or tears in the boot, etc).

 

Make darn  sure that both side throttle plate stop levers are FIRMLY on the idle stop screws. And make sure that you have a little slack in both lower cables.

 

I presume that all the valves are set correctly?

 

Make sure that you have no leaks in your manometer connections or  in the hoses at the U tube area connections.

 

The basic liquid manometer won't lie as long as the hoses & connection are not leaking so it shows what you have (engine wise).

 

Remember that you are dealing with a liquid manometer so it is VERY accurate & sensitive, most Hg or rod type balancing devices probably wouldn't show the difference so blatantly.

 

Added: that sure is one fancy looking manometer!

 

 

 

 

[kruuuzn]

Hey DR

 

But the BBS went from 3/4 to 2-1/2 on the left and 5/8 to 1 on the right. That difference concerns me.

 

I checked the TB boots and clamps. Good shape and tight.

 

Funny thing about the idle stops. You can hear them bottom out but when you look in there with a flash light they do not touch the stop screws. Both of them are quite a distance from the end of the stop screws.

Note: I'm not sure how to confirm the free play on the lower cables, and all I needed to do was shorten the left cable very slightly to balance the fluid levels.

 

I've checked and double checked the valves clearances. I've got them right on the money. I can't get a feeler gage to start that's a grand larger then spec.

 

I zipped tied the four tube connections that I have in the manometer. They're pretty tight.

 

And thanks for the compliment. The wife rolled her eyes when I broke out the white paint last night!

[dirtrider]

23 hours ago, kruuuzn said:

Hey DR

 

 

But the BBS went from 3/4 to 2-1/2 on the left and 5/8 to 1 on the right. That difference concerns me.--Yes just enough change to look into it.

 

I checked the TB boots and clamps. Good shape and tight.-- Good, that is accounted for.

 

Funny thing about the idle stops. You can hear them bottom out but when you look in there with a flash light they do not touch the stop screws. Both of them are quite a distance from the end of the stop screws.

Note: I'm not sure how to confirm the free play on the lower cables, and all I needed to do was shorten the left cable very slightly to balance the fluid levels. -- You will probably find your problem here as they positively need to be on the idle screws to get a valid idle balance.  Make sure that you have slack in the lower cables at idle as that is a must!  You absolutely need cable slack to get a good quality  base idle balance.

 

The TB throttle plate stop arms do not need to be on the idle stop screws to get a good above idle balance as they are not on the stop screws above idle but they MUST be on the stop screws for a valid base idle balance.  

 

If you have slack in your upper cable & the choke cable has slack (maybe back it off even more) then you might have to turn both side lower cable adjusters in equally  until the stop levers are on the stop screws. 

 

 Does it look like someone in the past has messed with the idle stop screws????? If those are adjusted incorrectly (ie  too far in) then the throttle plates might be seating tight to the throttle bores so they just can't close enough  to hit the stop screws. (you might need to unhook the cables at TB cams to verify that the TB's will close on the stop screws).  They can't be off of (properly adjusted) idle stop screws  too awful  far now as a normal nominal BBS setting is usually around 1-1/2 turns out from seated. 

 

I've checked and double checked the valves clearances. I've got them right on the money. I can't get a feeler gage to start that's a grand larger then spec.--Great.

 

I zipped tied the four tube connections that I have in the manometer. They're pretty tight.-- Again perfect.

 

And thanks for the compliment. The wife rolled her eyes when I broke out the white paint last night! --Well a job worth doing is worth doing correctly, personally I live by the same mindset.

 

____AGAIN, IF your throttle plate stop arms are not solidely resting on the stop screws at idle  then disconnect the cables at the TB cams & find out why! ___

 

[kruuuzn]

Thanks again for the help DR.

 

I now see the throttle plates stops are an issue but I'm still confused why the BBS settings changed so drastically before I adjusted the left throttle cable. If the stops aren't hitting now then they weren't hitting before either. All that was changed was a cleaning of the BBS's and a valve adjustment.

 

But putting that aside, it looks like I should start from the beginning to make this right. If I understand what you're saying I should add slack in both cables at the handle bars and then add slack to the bottom cables until the stop arms rest on the adjusting screws. Is that correct? The stop screw that we're taking about are threaded with lock nuts. How do we know they are in the correct location?

 

 

 

 

 

 

 

[Clive Liddell]

Hi Kruuuzn,

I don't see a floor fan in front of your bike?  With the tests you're doing you need to guard against overheating.  A large floor fan or two normal smaller fans blowing from the front are sufficient to keep the oil temperature and the exhaust headers under control.

 

Good luck with the throttle synching.  The good news is that once everything is set perfectly it seems to stay set for a long time!

 

[dirtrider]

7 hours ago, kruuuzn said:

Thanks again for the help DR.

 

I now see the throttle plates stops are an issue but I'm still confused why the BBS settings changed so drastically before I adjusted the left throttle cable. If the stops aren't hitting now then they weren't hitting before either. All that was changed was a cleaning of the BBS's and a valve adjustment.

 

But putting that aside, it looks like I should start from the beginning to make this right. If I understand what you're saying I should add slack in both cables at the handle bars and then add slack to the bottom cables until the stop arms rest on the adjusting screws. Is that correct? The stop screw that we're taking about are threaded with lock nuts. How do we know they are in the correct location?

 

 

Early Morning kruuuzn

 

Don't get too far ahead of yourself on this as you need to address it slowly & methodically without making changes that will take a lot of work & effort to correct.  

 

So, to begin with-- just cleaning the BBS screws & passages CAN effect the idle RPM & BBS screw setting afterwards (especially if they were dirty last time the balance was set)

 

I am having a difficult time with this as something doesn't seem correct with where you are at now.  (on one hand)--It sort of sounds like the throttle arms are not resting on the base idle screws at base idle,, (BUT on the other hand) if the throttle arms are NOT on the base idle screws  then you would think that the BBS screws would be turned in farther NOT backed out farther. (it takes very little throttle plate opening to really raise the idle RPM so  that would take BBS screws fully turned IN  to counter)

 

Basically if the throttles arms are not on the base idle screws then I usually find the BBS screws turned all the way in & the engine still has a very high idle (yours doesn't seem to be this way so it puts up a red flag for me).

 

So lets start with the idle stop screws before doing anything else--- ARE YOU ABSOLUTELY SURE that with the choke OFF  that there is  NOW an air gap at the stop screws?????? -- Check this every way that you can  before doing ANYTHING ELSE (strong light, paper stirp between the stop screw & arm). This absolutely needs to be verified/understood  before moving on.

 

If you (for sure) find an air gap at the base idle screws then we definitely need to find out why (hopefully they just 'look' like they are not touching but are really OK).

 

If you do find a verifiable air gap then unhook the cables from the TB  cams  (you should be able to rotate the cam in the open direction to put slack in the throttle cable  then hold it there, then (carefully)  work the cable end barrel out of the cam hole. Try not to disturb the basic cable adjustment or adjusters if possible.

 

With cables removed do you still have an air gap at the stop screws ???????????????? 

 

If the stop screw air gap disappears with the cables unhooked  then you need to find out why the cables were tight & holding them open.

 

A tight upper cable can hold them open, the choke (fast idle) wedge in the Boden Box not fully returned can hold them open, the pulley in the Bowden box all the way back/tight lower cables can hold them open, misadjusted idle stop screws can allow the throttle plates to bottom out inside the TB bores then THAT becomes the closed throttle stop not the screw.

 

I still have a BIG  problem in HOW the BBS screws need to be backed out more (let more air in)  but the TB stop arms don't appear to be resting on the stop screws. (this puts up a BIG red flag).

 

Do not take  big swings at this-- you need to slowly & methodically figure out WHAT IS GOING ON HERE.

 

I'm up early so away  on a off-road ride today,  I will TRY TO check in if/when I can but I might not have any internet connection all day/ 

 

Again, don't get ahead of yourself on this, go slowly & understand the problem, before making any corrections.

 

    

 

 

 

   

 

 

[kruuuzn]

3 hours ago, Clive Liddell said:

 

I don't see a floor fan in front of your bike?  With the tests you're doing you need to guard against overheating.  A large floor fan or two normal smaller fans blowing from the front are sufficient to keep the oil temperature and the exhaust headers under control.

 

 

Yup, I used a couple of fans and kept an eye on the oil temp. That pic was taken before I got started. Thanks for the heads up and your concern bud.

[roger 04 rt]

I can see at least one reason for your current predicament. In order to perform your idle TB sync, you loosened something (I can’t tell what from your posts).

 

That says to me that the throttles were off the stops before cleaning. Lossening anything (short throttle cables, fast idle cable or long throttle cable) would therefore close the throttles more, necessitating more open BBS settings.

 

Even following DR’s guidance closely, it would help you if you carefully read the link I sent earlier.

[kruuuzn]

1 hour ago, dirtrider said:

Don't get too far ahead of yourself on this as you need to address it slowly & methodically without making changes that will take a lot of work & effort to correct.  

 

 

I agree 100%. Taking big swings at this goes completely against my nature! LOL

 

On the stop screws; initially the gap looked open on the left side so I rotated the TB cam, slid my .006 valve shim in the gap, released the cam, and there didn't appear to be any drag.

THIS morning I got my feeler gages out and did this with a .002 shim. Then I gently put a little pressure on the cam and got the shim to drag. I would consider this closed for all practical purposes, wouldn't you? The way I see it, the little amount of gap we're taking about converts to almost NO rotation amount on the cam.

Sorry for getting this confused and starting down that rabbit hole. THIS is the reason I don't like taking big swings at things. If something doesn't make sense I always try to stop, take a breath, and think about it. And one thing I've learned over the years is that it ALWAYS looks better in the morning! hahaha......

 

Getting back to the BBSs. They were very clean when I removed them so I wouldn't think that would cause a big change in the settings.

 

It's funny though, I was happy with the results I got with my homemade manometer. It's those darn BBS settings that are bothering me.

 

One more question; why do they recommend you ride the bike to get the motor up to temp? Why can't you do that on the center stand and just keep an eye on the oil temp?