1994 1100 RSL Runs good BUT if u rev up it will give a loud backfire / pop when almost back to idle rpm..?? ideas..?

[Bill Cats]

1994 1100 RSL Runs good BUT if u rev up it will give a loud backfire / pop when almost back to idle rpm..?? ideas..?

( 45k miles ),, just purchased , dont have much history,,,,,

Seems to start good and runs very good ,,, but when coming to a stop if you give the customary little rev of the throttle, ( or even if at a stop in neutral ) it will rev  ( up ) nice BUT when the rpms are falling back to the idle mark it will give a nice pop / backfire most every time.... 

any ideas are welcome -- ( actually gets a little worse when it gets good and hot ) 

[Warren Dean]

Inaudible exhaust leak?

[9Mary7]

37 minutes ago, Warren Dean said:

Inaudible exhaust leak?

 

+1...... Does it have the stock exhaust system on it?, Aftermarket? Condition of system?

Popping out the muffler upon closed throttle returning to idle is usually the exhaust system sucking air in and igniting unburned fuel in the system.

[JamesW]

Don't know how long you've owned it but if you just found it have you gone through a complete fluids change and inspected tightness of nuts and bolts particularly the muffler/cat assembly to the head pipe?  Does it have a stock muffler?  Then I would do a very careful valve adjustment.  Really not too hard to do but does require a bit of homework on sites like this one.  Nothing special tool wise accept two sets of feeler gauges.  Takes me about an hour to do mine.  Might not be a bad idea to check the throttle body sync while you're at it.  Easy to do but takes practice and patience.  What I'm saying is you need to get your feet wet and really find out what you've got in general.  

 

Ain't she pretty?

 

[JamesW]

I would also remove the side covers which is super easy to do and look carefully at the throttle bodies.  When you gently advance the throttle watch to see that the throttle cable to each throttle body starts to move at the same time as you begin to turn the throttle up.  

 

When you say it runs good does it vibrate at all or blur the mirrors when you advance the throttle at idle?  For smooth engine operation those throttle bodies need to be in very close sync.  Not hard to do but takes practice especially because of the somewhat weird single throttle cable that controls not one but both throttle bodies.  It's a cool way to do it but does have a tendency to infuriate. Again, google is your friend.  Have fun.  And who knows, after you've checked and done all these things your backfire might be history.

 

Just thought of something else.  A loose timing chain can cause backfiring.  There was a mod for these bikes which involves a new timing chain tensioner which is super easy to install.  On a cold start up does it rattle?

[dirtrider]

11 hours ago, Bill Cats said:

1994 1100 RSL Runs good BUT if u rev up it will give a loud backfire / pop when almost back to idle rpm..?? ideas..?

( 45k miles ),, just purchased , dont have much history,,,,,

Seems to start good and runs very good ,,, but when coming to a stop if you give the customary little rev of the throttle, ( or even if at a stop in neutral ) it will rev  ( up ) nice BUT when the rpms are falling back to the idle mark it will give a nice pop / backfire most every time.... 

any ideas are welcome -- ( actually gets a little worse when it gets good and hot ) 

Morning Bill

 

Does it pop on decel when actually riding the motorcycle, or only pop when free-revving in place? (this might help us determine where your problem is) 

 

As mentioned above the exhaust system is the usual cause so you first need to determine IF it still has the original BMW exhaust system.

 

Your picture shows the wrong side but it looks to have the original cat converter & front exhaust system.

 

So your muffler is probably still stock (but verify that).

 

If a stock exhaust system then use a strong flashlight & look into the rear of muffler, does the internal baffler look like it is in good shape & not all rusted away? (see picture below)

 

Next, look on the catalytic converter body for the 2 tabs that are welded to it, some 1100 bikes cracked the cat housing right where those tabs are welded on. If you have any cracking in that area that will cause the dropped throttle popping. 

 

Next, get some help then have your helper put on a heavy leather glove, then have them force a large rag into the rear of the muffler with the engine running (caution that exhaust system gets very hot). Have them hold that rag as tight as they can without stalling the engine. 

 

While the rag is held in the muffler look & listen around under the motorcycle for an exhaust leak (if you find one then that leak is probably causing the dropped throttle popping).  

 

If no leaks found in the exhaust then you might have a slightly dripping fuel injector as it returns to idle (this is difficult to find) 

 

Or a mis-adjusted TPS (Throttle Position Sensor)  could be changing the dropped throttle fuel cut-off point (electronics shuts the fuel to the injectors off on dropped throttle until the RPM's get back to near idle). If that is off it might still be fueling on dropped throttle.

 

Any chance that motorcycle has an aftermarket fuel controller on it?  (probably be some sort of non-OEM box under the seat)?

 

So make sure it still  has the stock exhaust system/

 

Make sure that the inside of muffler isn't all rotted out/ 

 

Then CAREFULLY check the exhaust system for leaks (especially around those welded on tabs)/

 

If it still runs & rides OK then try some Techron concentrate in the fuel tank for a couple of tank full's, this might clean up a dripping fuel injector (if that is the problem)/

 

If the problem is still there then you might have to check the TPS adjustment/ 

 

 

 

 

 

 

 

 

[Bill Cats]

First I want to say thank you for your explanations, and taking the time to write what you did it means a lot to me that you actually paused your life to answer in such detail :-) I should be more clear, the stock exhaust is on the bike, I don't see any fuel management systems under the tank, and it only pops free revving, and only once, one single pop on the deceleration side of a free rev, doesn't pop much , if at all when decelerating, but very noticeable and loud and ONE single pop ( every time, like clock work )  right when returning to the idle speed, thank you very much I wait your answer,

[Bill Cats]

8 hours ago, JamesW said:

I would also remove the side covers which is super easy to do and look carefully at the throttle bodies.  When you gently advance the throttle watch to see that the throttle cable to each throttle body starts to move at the same time as you begin to turn the throttle up.  

 

When you say it runs good does it vibrate at all or blur the mirrors when you advance the throttle at idle?  For smooth engine operation those throttle bodies need to be in very close sync.  Not hard to do but takes practice especially because of the somewhat weird single throttle cable that controls not one but both throttle bodies.  It's a cool way to do it but does have a tendency to infuriate. Again, google is your friend.  Have fun.  And who knows, after you've checked and done all these things your backfire might be history.

 

Just thought of something else.  A loose timing chain can cause backfiring.  There was a mod for these bikes which involves a new timing chain tensioner which is super easy to install.  On a cold start up does it rattle?

He gave me a ( upgraded timing chain tensioner) , new one ,,, and said it would rattle  IF I haven't driven the bike for a long time for just a second or so,, but I have not heard it , and he said he didn't get around to installing it , ,

[dirtrider]

11 minutes ago, Bill Cats said:

First I want to say thank you for your explanations, and taking the time to write what you did it means a lot to me that you actually paused your life to answer in such detail :-) I should be more clear, the stock exhaust is on the bike, I don't see any fuel management systems under the tank, and it only pops free revving, and only once, one single pop on the deceleration side of a free rev, doesn't pop much , if at all when decelerating, but very noticeable and loud and ONE single pop ( every time, like clock work )  right when returning to the idle speed, thank you very much I wait your answer,

Morning Bill

 

OK, that helps a little __

 

As a rule a leaking exhaust will also pop on dropped throttle even while riding so that somewhat eliminates the exhaust system leak (not totally eliminated but somewhat eliminated).

 

If only popping on dropped throttle in neutral then possibly the fuel cut off/cut in point is causing it. 

 

When you free-revv in neutral then  release the throttle that s-h-o-u-l-d completely turn the fueling off until teh RPMs drop to just about idle. A slightly dripping injector can  cause that neutral dropped-throttle pop. (so try the Techron)

 

You might eventually want to check the TPS adjustment also as there is a voltage threshold that effects fuel cut-off. 

 

Any chance that you have a higher than normal warm engine idle? That can also effect the TPS setting & effect dropped throttle popping. 

 

 

 

 

[Bill Cats]

The idle is at 1k and sounds like it's very slow,,, and I would check the tps adjustment, is it difficult ,??? Is there a posted process posted,, ? I ordered the valve tools from beemer boneyard ?? And he gave me the tool to sync throttle bodies )) , so also have the upgraded cam chain tensioner,,

Can u recomend the links and order of completing these things ? 

[dirtrider]

3 hours ago, Bill Cats said:

The idle is at 1k and sounds like it's very slow,,, and I would check the tps adjustment, is it difficult ,??? Is there a posted process posted,, ? I ordered the valve tools from beemer boneyard ?? And he gave me the tool to sync throttle bodies )) , so also have the upgraded cam chain tensioner,,

Can u recomend the links and order of completing these things ? 

Afternoon Bill 

 

Do the  upgraded cam chain tensioner first & get that out of the way.  Won't effect your popping but it needs to be done.

 

Then ride a few new tank fill-up's using Techron concentrate in the fuel, this will somewhat clean the fuel system  & hopefully get the fuel injectors spraying a good pattern. 

 

Then do the valve adjustment (that needs to be done BEFORE the throttle body sync).

 

Before finalizing the idle RPM (1050 to a low 1100 is a good hot engine idle RPM) definitely clean the throttle body  BBS (Big Brass Screws) screws & the by-pass air passages under the BBS screws.  

 

Then check the TPS adjustment (you need a good digital voltmeter to do this).

 

There are online procedures to do all the above but some are not correct or  can be misleading so search around then come back & ask here before proceeding. 

 

You need to FULLY understand the procedures BEFORE attempting to do any of them. 

 

Do the throttle body balance & final idle  RPM setting last. 

[JamesW]

Hi Bill,

DR....He-da-man and he'll keep you straight.  You have, imo, one of the best bikes BMW ever made.  But, as I have learned, you are kind of on your own especially depending on where you live.  So many BMW dealers won't work on older models so us guys with older bikes like we have are literally on our own when it comes to maintenance and troubleshooting.  Where I live the best BMW dealer in the state was destroyed totally by fire in September so it's just me for the foreseeable.  I always felt good just knowing I could depend on Hansen's BMW if the need arose but sadly no more.  If I were you I would invest in a Haynes manual that and this web sight and google will keep you straight.  

[Bill Cats]

Ok and sounds good ,, to clean the bb screws do u back them out all the way  ( noting there exact position ) and shoot some carb cleaner in there ?? 

I'll b pulling the plastics off tomorrow )) 

[dirtrider]

7 hours ago, Bill Cats said:

Ok and sounds good ,, to clean the bb screws do u back them out all the way  ( noting there exact position ) and shoot some carb cleaner in there ?? 

I'll b pulling the plastics off tomorrow )) 

Morning Bill

 

Sort of__

 

First, you need turn each BBS screw all the way in until lightly seated while counting the exact number of turns & partial turns in (so you can put them back to where they were when done). Most likely they are now somewhere in the 1 to 2 turns out from lightly seated neighborhood. 

 

Next, remove the BBS screws then remove the hoses (or vacuum caps) from the fittings on the bottom of the throttle bodies (this allows the cleaning fluid to run out those bottom throttle body fittings). Personally I then put a short length of bulk hose on each lower throttle body fitting so the carb cleaner & gunk runs into a catch container & away from the motorcycle as carb cleaner can damage paint.

 

If possible use o2 sensor safe carb cleaner to clean the BBS seats & air passages that are under the BBS screws as you don't want to damage your o2 sensor. 

 

Then clean the BBS screws & inspect the BBS screw O rings (if O rings are damaged then replace them).

 

When all clean then reinstall the BBS screws in the same side they were removed from then turn in until lightly seated, then back each side out the same number of turns that  you counted before removal. 

[JamesW]

Hi again Bill.  Just thought of something else.  I used to own a '04 R1150RT and I had the catalytic converter removed from its enclosure which is part of the muffler/cat assembly.  My 1150 had a slight lean surge issue and I connected a fuel enricher device to attempt a remedy.  After I had the CAT removed I would get backfiring because the empty cat chamber would tend to collect unburned fuel then ignite producing the backfire.  Maybe the previous owner modified the fuel system to combat these early oilhead's pronounced tendency to surge.  When I first obtained my '93 R1100RSL the bike had a very bad surge to the point it was almost impossible to enjoy riding.  I fixed the problem with installation of a wideband O2 sensor but that's another story and I definitely learned on the '04RT to leave well enough alone and not remove the CAT.  lol..lol..  Anyway, just something else to think about and maybe the previous owner or maybe the one before him reamed out the CAT chamber to destroy the cat you never know when it comes to 26 year old bikes especially BMWs since these owners especially like to tinker it seems not that I'm guilty of that.

[dirtrider]

1 hour ago, JamesW said:

Hi again Bill.  Just thought of something else.  I used to own a '04 R1150RT and I had the catalytic converter removed from its enclosure which is part of the muffler/cat assembly.  My 1150 had a slight lean surge issue and I connected a fuel enricher device to attempt a remedy.  After I had the CAT removed I would get backfiring because the empty cat chamber would tend to collect unburned fuel then ignite producing the backfire.  Maybe the previous owner modified the fuel system to combat these early oilhead's pronounced tendency to surge.  When I first obtained my '93 R1100RSL the bike had a very bad surge to the point it was almost impossible to enjoy riding.  I fixed the problem with installation of a wideband O2 sensor but that's another story and I definitely learned on the '04RT to leave well enough alone and not remove the CAT.  lol..lol..  Anyway, just something else to think about and maybe the previous owner or maybe the one before him reamed out the CAT chamber to destroy the cat you never know when it comes to 26 year old bikes especially BMWs since these owners especially like to tinker it seems not that I'm guilty of that.

Afternoon James

 

I have gutted a number of BMW oilhead cats, the exhaust does become louder & sometimes a little muffled popping on a long decel but I never had one the would only pop revving in neutral but then not  pop while riding.   Bill says his doesn't pop while riding, only when revving in neutral.  

[JamesW]

42 minutes ago, dirtrider said:

Afternoon James

 

I have gutted a number of BMW oilhead cats, the exhaust does become louder & sometimes a little muffled popping on a long decel but I never had one the would only pop revving in neutral but then not  pop while riding.   Bill says his doesn't pop while riding, only when revving in neutral.  

 

Hi DR, I go along with that.  That is how my 1150 acted as well until I installed the mixture adjuster.  It would load up at idle in neutral then pop or backfire when revved a bit.  If I remember right I would also get, rarely, an extremely loud backfire when riding I think because I was experimenting with code plugs.  Can't remember the name of the device I first installed and I was playing around with different code plugs at the time as well.  My R1100 doesn't have a physical code plug and probably Bill's doesn't have one either.  I say probably with tongue in cheek knowing BMW.  I would love to lay hands on Bill's bike.  Then again the R1100 used the 2.2 Motronic whereas the 1150 was the 2.4 so can't really directly compare the two come to think of it.

 

I also wonder about the timing on Bill's bike although if you rotate the HES timing adjustment stop to stop it only affects actual timing by not that much.  Maybe 6 degrees? I know I tried it with mine once and it didn't affect performance much at all that I could tell and didn't cause backfiring just maybe idle RPM a bit.  Don't think the HES has anything to do with the problem but would be interesting to put a timing light on it, maybe?  Big question in my mind with Bill's bike is what have previous owner's done?

[dirtrider]

8 minutes ago, JamesW said:

 

Hi DR, I go along with that.  That is how my 1150 acted as well until I installed the mixture adjuster.  It would load up at idle in neutral then pop or backfire when revved a bit.  If I remember right I would also get, rarely, an extremely loud backfire when riding I think because I was experimenting with code plugs.  Can't remember the name of the device I first installed and I was playing around with different code plugs at the time as well.  My R1100 doesn't have a physical code plug and probably Bill's doesn't have one either.  I say probably with tongue in cheek knowing BMW.  I would love to lay hands on Bill's bike.  Then again the R1100 used the 2.2 Motronic whereas the 1150 was the 2.4 so can't really directly compare the two come to think of it.

Afternoon James

 

Yes, the early 1100RS didn't have a CPP in the fuse box (Coding Plug) but they did have some wires in the harness that could be cut to change the coding slightly. It's been so long I would have to look it up to see what changes were available (AFAIR not many).

[JamesW]

2 minutes ago, dirtrider said:

Afternoon James

 

Yes, the early 1100RS didn't have a CPP in the fuse box (Coding Plug) but they did have some wires in the harness that could be cut to change the coding slightly. It's been so long I would have to look it up to see what changes were available (AFAIR not many).

 

Yes, that's the way my 1100 is also.  I think it is the equivalent of a yellow code plug in affect.

[Bill Cats]

On 12/1/2020 at 11:52 PM, JamesW said:

Don't know how long you've owned it but if you just found it have you gone through a complete fluids change and inspected tightness of nuts and bolts particularly the muffler/cat assembly to the head pipe?  Does it have a stock muffler?  Then I would do a very careful valve adjustment.  Really not too hard to do but does require a bit of homework on sites like this one.  Nothing special tool wise accept two sets of feeler gauges.  Takes me about an hour to do mine.  Might not be a bad idea to check the throttle body sync while you're at it.  Easy to do but takes practice and patience.  What I'm saying is you need to get your feet wet and really find out what you've got in general.  

 

Ain't she pretty?

 

Ps that's my EXACT bike with a black seat ))!!

[JamesW]

lol..lol..It's all good.  Mine originally had a green seat.  I used to get made fun of.

[Bill Cats]

Ok ,,,

I JUST bought her from a guy named " Bill " in Delaware,, ( about 65 - 70 ) 

My bike ie the exact color as yours James W,

He gave me a stay tuned exhaust AND said he took it off because of the  "Popping "  noises,

He also said he was on the Boards for a long time and he " MIGHT " Have said he was a administrator - which is why i bought the bike ,,

He gave me the after market exhaust in my hand AND a long looking " tube - air - tube - black - ( OR tubes ) ill look tonight to see if there is 2 or just one,,

I " think " he mentioned that he " may have changed them " 

He also gave me a Throttle balancing device that works on a vacuum principal, with a dial in the center - Super smart - guy, engineer - 

Didn't think he would put up with a popping issue sssooo i was betting it wouldn't be an easy one,,, as he has had the bike like 10 years - 

I ordered the valve adjustment feelers from boneyard,

Plan of attack is as follows - 

 

- Pull the plastic tonight , leave it off and go for CAM chain tensioner on left,, he told me that's the side that's intermittently noisy,,, -  

 - Ill check back in )))) 

 - PS - can someone provide me a link for the EASIEST method to set the TPS - I have a good digital volt meter - and can be dangerous with it ))) and an O Scope -  ( 1994 RSL )) 

 

[dirtrider]

44 minutes ago, Bill Cats said:

Super smart - guy, engineer - 

Didn't think he would put up with a popping issue sssooo i was betting it wouldn't be an easy one,,, as he has

 

Evening Bill 

 

He might not have heard it as most knowledgeable old BMW 1100 owners tend to not revv the engine much in neutral due to the engine being air cooled & revving in neutral while sitting still there isn't any air flowing over the engine & exhaust.

 

The front exhaust pipes run real close to the plastic panels so it doesn't take long to damage the plastics if the RPM's are run up sitting still.

 

If you work on that bike with the plastics still on it be sure to use a fan (or better yet 2 fans) to keep cool air blowing on the engine so you don't damage your plastics.  (at night if you revv it bit sitting still you can actually see the pipes turn glowing red)

 

On the TPS setting, I haven't the time right now to do a write up so see if someone posts a procedure, if not I will try to do a procedure for tomorrow. 

 

You should probably  clean the BBS screws & get the idle close & do a valve adjustment  before checking the TPS, if you can't get that (the idle RPM)  within reason you might  need to do a base idle reset & that will require a new TPS adjustment.   

[JamesW]

Bill, I wonder if anyone has done what is called a canisterectomy on that bike.  If so on the underside of each throttle body you will find a vacuum port that either has a plug or cover (usually a rubber cap) over it.  These two ports are where you connect the vacuum gauges. Make sure they both have a cap over them and that they are not uncovered.  If no canisterectomy then you will find vacuum lines connected to the ports and if so both should be connected so neither port is ever left open to outside air.  The canisterectomy is another story.  It was the first thing I did to my R1100.  Again google is your friend.

[Miguel!]

1 hour ago, JamesW said:

Bill, I wonder if anyone has done what is called a canisterectomy on that bike.  If so on the underside of each throttle body you will find a vacuum port that either has a plug or cover (usually a rubber cap) over it.  These two ports are where you connect the vacuum gauges. Make sure they both have a cap over them and that they are not uncovered.  If no canisterectomy then you will find vacuum lines connected to the ports and if so both should be connected so neither port is ever left open to outside air.  The canisterectomy is another story.  It was the first thing I did to my R1100.  Again google is your friend.

Have a look at these videos from Chris Harris. I followed his procedure and removed the canister and the excess hose. I recently threw the canister into the recycling bin after offering it here to see if anyone wanted it. 

Removing the canister didn't eliminate the relatively-quiet "pfft, pfft" backfires I get when slowing down in gear.

Miguel 

[dirtrider]

Morning Bill

 

Before starting the TPS check or adjustment you need to make sure that the choke is OFF, that you have some slack in the L/H throttle cable, & that the L/H side throttle body cam is solidly returning to it's base idle stop. (this is a must before proceeding). 

 

Next, you need to find a way to connect your voltmeter to the TPS terminals 1 & 4 with the harness connector still plugged into it.

 

Some use a single copper wire strand  removed form a lamp cord or from a multi-strand wire. That single strand of copper wire is carefully placed between the TPS  terminals & the harness connector terminals as the harness connector is plugged back in (difficult but doable).

 

Others try to work an opened safety pin or open paper clip up into the back of the TPS connector past the moisture seal (without damaging the moisture seal). Or some try to work the moisture seal down a little then insert an open paper clip into the rear of the TPS connector on terminal 1 & 4.     

 

Personally I use a short break-out harness that plugs in between the TPS & the removed harness connector. This is very difficult to duplicate as the TPS side terminal area is very difficult to duplicate or find a matching connector for. 

 

In any case you need find a way to connect your voltmeter between the TPS terminals 1 & terminal 4 with TPS connector plugged in. TPS wire colors are   pin 1 = white/red, pin 2 = green/yellow, pin 3 = white/gray, pin 4 = brown/gray.  Never pierce the TPS wire insulation to make the connection as that allows moisture to enter the wire .  

 

You need your digital voltmeter on the lowest DC scale that will read up to 5+ volts  (usually 12v dc or 20v dc). Meter connection polarity doesn’t really matter but meter red (+) lead to TPS terminal (1) will give the correct voltage polarity reading on the meter.  

 

You need a very accurate meter reading to thousands of a volt so before connecting the meter you might put it on the Ohm setting then touch the meter leads together to verify that your meter doesn’t have any resistance in the meter leads or lead connections.

 

Once your meter is connected to the TPS terminals 1 & 4, & your meter is back on the DC voltage setting & you are SURE that the L/H side throttle body cam is solidly contacting the base idle screw, you are now ready to check or re-set the TPS.

 

With key turned on (engine not running) & throttle cam solidly on the base idle screw (but don’t hold it their by hand), you need to see the TPS voltage under .399 volts. Anything between .365v & .385v is good. Personally I set the 1100 (Ma 2.2 Motronic) to .380v-.385v. Roger sets then them a bit lower.

 

You set the TPS by loosening the TPS retaining screws then rotating the TPS until you get the voltage that you need to see. Then tighten the TPS screws. Next open & close the throttle a couple of times & verify that the TPS voltage drops back to your desired setting.  The TPS voltage ALWAYS needs to drop back to under .399v at closed throttle. If it doesn’t then find out why it isn’t doing that.

 

After checking (or re-setting) the TPS per above you next need to slowly open the throttle to wide open throttle while watching your voltmeter. It needs to smoothly scroll from your base setting of .365v-.385v to 5v then smoothly scroll back to the base setting. If the TPS voltage doesn’t scroll smoothly up to 5v then back down to under .399v  find out why.   

[dirtrider]

11 hours ago, JamesW said:

Bill, I wonder if anyone has done what is called a canisterectomy on that bike.  If so on the underside of each throttle body you will find a vacuum port that either has a plug or cover (usually a rubber cap) over it.  These two ports are where you connect the vacuum gauges. Make sure they both have a cap over them and that they are not uncovered.  If no canisterectomy then you will find vacuum lines connected to the ports and if so both should be connected so neither port is ever left open to outside air.  The canisterectomy is another story.  It was the first thing I did to my R1100.  Again google is your friend.

Morning James

 

His picture above shows it already removed.

[JamesW]

56 minutes ago, dirtrider said:

Morning James

 

His picture above shows it already removed.

 

Hi DR, sorry can't find the picture you're referring to.  I posted a pix of my bike but can't find one Bill has posted, sorry.  I think I'm going to hide in the weeds here as too many cooks spoil the soup and he's in good hands with you.

[dirtrider]

10 minutes ago, JamesW said:

 

Hi DR, sorry can't find the picture you're referring to.  I posted a pix of my bike but can't find one Bill has posted, sorry.  I think I'm going to hide in the weeds here as too many cooks spoil the soup and he's in good hands with you.

Morning James

 

You are correct, I saw the picture above & thought that was Bill's bike. That is a nice looking RS.

 

Do stick around in this thread as you probably know more about the oddball 94 1100RS than I do. Those things are definitely an outlier.  Even the crankcase venting system is strange on those early 1100RS bikes. 

[JamesW]

Hi D.R., Yes, outlier is a great description lol..lol.. Besides the crank case vent system I wish BMW would have put an oil temp thermostat on these early oilheads.   I was also wondering if a leaky fuel injector(s) could maybe have anything to do with Bill's issue.  I will be interested to see how the issue is resolved.

[dirtrider]

1 minute ago, JamesW said:

Hi D.R., Yes, outlier is a great description lol..lol.. Besides the crank case vent system I wish BMW would have put an oil temp thermostat on these early oilheads.   I was also wondering if a leaky fuel injector(s) could maybe have anything to do with Bill's issue.  I will be interested to see how the issue is resolved.

Evening James

 

Yes, dripping fuel injector or injectors very easily could be causing his issue. I mentioned that early in this thread & suggested that he run some Techron though it. 

 

That is the problem with these longer threads, things mentioned early in the thread can get overlooked as they get buried in all the text & many posts.  

 

 

[Bill Cats]

[Bill Cats]

[Bill Cats]

I " hope " this is not bad educate to post the pics here,,,,,

IF so it wont happen again,,,,

 

I did want to show James W , DR and the folks on the thread the bike,,

So the shocks are " custom " valved for a 170 lb. rider I'm told ( PS - that happens to be my weight - )

Air tubes were changed  - I'm not sure if the stock ones are on the bike,,

the Stay Tune - full exhaust  - is not on the bike,,-

the fuse box under the seat does not show any after market stuff ( i don't think ) 

- i bought the new tire - it needs it - front - 

- the TPS Sensor "looks " stock " and i DONT see any paint on the screw heads BUT the gentlemen i bought it from said he " seen no benifit from the zero -zero procedure "  - i had / have no idea what that means - 

 

- the cam chain tensioner IS 17mm on left hand side BUT the one is a bag with NO o rings or crush washers  - is 15mm -

my valve setting tools STILL are not here yet ;))

- issue is ( ONE pop - backfire - sounds deep in the catalytic converter ) when returning to the idle of a little over 1000k ) - 

PS - the PO said he did not mess with the CAT - 

Bile looks and runs very nice BUT for that issue - it all  seems a bit overwhelming at this point,,, I think I'm doing the Cam chain tensioner first as instructed by you folks,,, then I " think" I'm skipping the TPS - ( not sure about that one ) --- and moving on to setting the valves and then the sync - ( i have done that before with a jap bike so I feel somewhat good about hat procedure and after reading i do understand about the Brass screws and how the throttle cables split into 2 causing a unique point of interest --- 

[dirtrider]

4 hours ago, Bill Cats said:

I " hope " this is not bad educate to post the pics here,,,,,

IF so it wont happen again,,,,

 

I did want to show James W , DR and the folks on the thread the bike,,

So the shocks are " custom " valved for a 170 lb. rider I'm told ( PS - that happens to be my weight - )

Air tubes were changed  - I'm not sure if the stock ones are on the bike,,

the Stay Tune - full exhaust  - is not on the bike,,-

the fuse box under the seat does not show any after market stuff ( i don't think ) 

- i bought the new tire - it needs it - front - 

- the TPS Sensor "looks " stock " and i DONT see any paint on the screw heads BUT the gentlemen i bought it from said he " seen no benifit from the zero -zero procedure "  - i had / have no idea what that means - 

 

- the cam chain tensioner IS 17mm on left hand side BUT the one is a bag with NO o rings or crush washers  - is 15mm -

my valve setting tools STILL are not here yet ;))

- issue is ( ONE pop - backfire - sounds deep in the catalytic converter ) when returning to the idle of a little over 1000k ) - 

PS - the PO said he did not mess with the CAT - 

Bile looks and runs very nice BUT for that issue - it all  seems a bit overwhelming at this point,,, I think I'm doing the Cam chain tensioner first as instructed by you folks,,, then I " think" I'm skipping the TPS - ( not sure about that one ) --- and moving on to setting the valves and then the sync - ( i have done that before with a jap bike so I feel somewhat good about hat procedure and after reading i do understand about the Brass screws and how the throttle cables split into 2 causing a unique point of interest --- 

Morning Bill 

 

Good to have a basic picture or two but the problem in posting a lot of pictures is that it makes the threads way longer than they need to be so things get lost in the clutter as threads get too long for most to read through & keep on point. 

 

When the thread starts getting long (like this one) it is a good practice, & you will get better feedback, if you start a new thread with each new question (or each new set of questions).  

 

I will try to keep up & address a few of your above concerns___ 

 

First off the 0=0 was an old way to restore the base idle screw position using the TPS output, it doesn't work using 0=0 & has been proven wrong for  a long time now (never use 0=0 for any tuning). 

 

Your bike came with the shorter air tubes, the longer ones were usually from the 1100 GS bike with different base tuning. Some installed the longer GS air tubes to reduce surging & improve the mid-range but it didn't really help surging & was marginal on the midrange help. You can leave the longer ones in or replace with the shorter ones as you probably won't be able to tell much difference. 

 

Your pictures show the evap can already removed so that is a plus. 

 

The 17mm tensioner is the old original, the 15mm is newer 1200 hexhead tensioner with inverted piston (some call it the "improved" when used on the 1100/1150 engines).

 

On your throttle cables-- be careful in what you read as you have an early 1100 bike, that doesn't use split cables with bowden box like the later 1100 & 1150 bike.  Your bike has one continuous cable from the twist grip going to the L/H throttle body cam then wraps around the L/H side & continues on to the right hand side throttle body cam.

It works OK but does have a some quirks when doing a throttle body synchronization. 

 

When you get ready to do a throttle body sync post that in a new thread here as there are some important things to consider when syncing a single cable system. 

 

On the valve adjustment-- the big got-ya on that is to be very careful in re-installing the valve covers,  the valve cover bolts have a stop that bottoms out on the cylinder head boss so once that stop contacts the cyl head boss it is ever so easy to strip the threads out of the cylinder head. If you use a torque wrench then make sure that it is a very low torque reading wrench. Or just use  a very short 1/4 drive ratchet (the shorter the ratchet handle the better).

 

One last thing-- do be very careful in what you read in older threads or other on-line info to be DARN SURE that it pertains to your (very early) 1100RS motorcycle. The early 1100RS is an outlier  with some subtle & some not so subtle differences. Some 1100RT, GS info does apply to your motorcycle but some is way wrong so be certain that the info that your read also pertains to your early 1100RS.  

 

  

 

 

[JamesW]

Good morning to you Bill,  That is a nice looking early oilhead.  I noticed in the pix that your front turn signal lenses are clear, kind of interesting other than that she looks like mine.  If you look on the steering head you will see along with the VIN the month and year of manufacture. I would be interested in the build date of your bike.  Mine is 06/93 and is the 685th oilhead produced.

 

I was thinking that it might be interesting to, with digital VM, just check the TPS voltage and make note of it then rotate the TPS to within the voltage range DR gave you in a previous post if it isn't already there might affect the idle revs a bit especially if you increase the voltage which is OK if you don't go much over 1100 RPM at idle with warm engine.  If need be you can always set the TPS back to what it was after you test for backfire.  Would be no harm no foul.  Check the volts and make any adjustment with just the key on and bike not running.  Pretty easy peasy.  If, by chance, your backfire clears up and all else is OK I'd just call it good.  Interesting the previous owner played around with the TPS.  I also wonder how close to the mid position your TPS is now and how close to center it might be should you adjust it.  If you do try to set the volts to DR specs I would shoot for the higher voltage keeping in spec of course.

[Bill Cats]

" Good morning to you Bill,  That is a nice looking early oilhead.  I noticed in the pix that your front turn signal lenses are clear, kind of interesting other than that she looks like mine.  If you look on the steering head you will see along with the VIN the month and year of manufacture -"

 

James W,, sorry for the lag in response  - VIN   -   WB1041603R0311109    -   i would love to know if you can decode this a little for me ))   i got my tire mounted - the brakes were SUPER thin - so i seen a set of pads that the PO gave me,, - i replaced them and put  it all back together to find horrific  DRAG in the front wheel - ( ended up being a bad brake line with an internal break i speculate ) and yes  i did NOT let them hang or get tugged - i hung them from wire,, i " think " tit was bad as i had a flashing abs lite since purchase but was working on the backfire first - so i ordered some aftermarket ones after searching and finding - out of stock  on everything under like 150 dollars,  or from Germany and just as used as what i had ) - link to what i purchased ---  https://www.ebay.com/ipp/282887082812?transactionId=2222618401018&_trksid=p2047675.l48352 - ( I know its junk BUT while I'm searching it must do ) 

- Sometimes when i get pissed i just walk away for a few days )))

 

"I was thinking that it might be interesting to, with digital VM, just check the TPS voltage and make note of it then rotate the TPS to within the voltage range DR gave you in a previous post if it isn't already there might affect the idle revs a bit especially if you increase the voltage which is OK if you don't go much over 1100 RPM at idle with warm engine"

Next on my agenda is to  give the TPS Measurements that you - ill read the DR post and ( try ) as i have a good meter - 

 

I also got my valve clearance tools from the boneyard sssooo on my next outing to the garage its TPS measurements first ,,, then the valve check - )))

 

[Bill Cats]

On 12/5/2020 at 1:57 PM, JamesW said:

 

 

On 12/5/2020 at 11:39 AM, dirtrider said:

Morning Bill 

Good to have a basic picture or two but the problem in posting a lot of pictures is that it makes the threads way longer than they need to be so things get lost in the clutter as threads get too long for most to read through & keep on point. 

 

Starting a new thread on the TPS work im doing next ;))  Thanks for the Tip on this to keep the threads manageable ;))) 

[Bill Cats]

Been a while BUT just to close the loop on this one -

- checked compression - 155psi #1         165psi #2

- repaired air cleaner box - tabs that hold top snapped down were broke - pot top in place and secured - 

- set the valves ( they were tight ) exhaust valves could not get feeler through

- removed Throttle bodies and cleaned - omg black inside both,,, 2 cans of car cleaner, even blew it up in injectors - 

- balanced cylinders ( way off ) 

 

FIXED - thank you all

 

[Gary E Reynolds]

Did you replace the factory exhaust? 🥴

[Bill Cats]

i performed a full tune up --- fixed ,,, thank u very much