syncn-tbi

[rustyfingerz]

 

after a little hemming and hawing, i decided an attempt at valve adjustment.

using "oilhead valve adjustment for dummies". kudos to the three gentlemen [no disrespect intended] who made the above undertaking most effortless.

now for the subject matter @ hand. again relying on the wisdom of "three" obtained a copy of "oilhead throttle body synching for dummies",

Dialed in my twin max, made a note of the BBAS settings. Here is were I hope for patience within this "collective".

I cannot seem to maintain a constant balance/reading if you will once I get the needle on the twin-max to zero in. Another words, once I get my idle speed up to 1150rpm, and have adjusted the BBAS's to T-M specs, starting from min sensitivity all the way up to max, I think I have it until I shut down the engine,

get a beer, take a leek what ever, putting the T-M on min sensitivity, re start engine, and its like I have to start all over again.

re turning the BBASs back to original settings and readjusting them all over again,and again. One observation during all this, the left side TBI is more responsive to adjustments. The right side BBAS can all but be closed be for noticing any reaction.Opening gives no noticeable action.

To say its the week side is an understatement. The "instructions" do mention the possibility of a " vacuum leek some where" or an" underlining issue somewhere".

Sorry for the long post,But some input from any TBI sync experts would be greatly appreciated.

Thanks In Advance

Mark

 

[dirtrider]

Morning Mark

 

Sounds a little like your right BBS screw and passage under it might be partially blocked with coke or crud.

 

First off—count the turns to fully seat the BBS screw (so you can put it back to where it was), then remove the BBS screw and clean the screw tip, then use some (cat & 02) friendly spray carb cleaner to clean the BBS passage (might also need to use a small soft wire). Might just as well clean both sides while doing it.

 

Also make darn sure you throttle cables are not too tight at hot curb idle (needs to be a little slack at hot engine choke-off idle).

 

If you find a lot of black coke in the BBS passage you probably should also slide the air tubes back into the air box and use the cleaner to clean the area around the throttle plates and TBI bore as that area being coaked up can have an adverse effect on repeatable air flow as the throttle valves close.

 

[rustyfingerz]

Back from cigar shop,pack of pipe cleaners,one cuban rum[for later]

[rustyfingerz]

I had done the timing chain tensioner upgrade recently, and when I had the

left side TB off I did all the "house keeping" as it were.

I guess the other side was jealous. I did disassemble and clean. as you said, not very nice.

Adjusting the BBASs, there was more of a noticeable response making that part of it much easier. Then attempted the high speed adjustment.dialed that in,little by little with cable adjuster.that changed the idle adjustment a little so I just went back and forth fine tuning both until they were dialed in and synched.Read some were instead of putting rubber caps under the TB vac inlet. run a vacuum line from one TB to the other TB, what do you think of this practice? advantages/disadvantages?

 

Thanks

Mark

[dirtrider]

----Read somewere instead of putting rubber caps under the TB vac inlet. run a vacuum line from one TB to the other TB, what do you think of this practice? advantages/disadvantages?

Mark

 

Afternoon Mark

 

Won’t hurt but also won’t make a significant difference. That hose is so small and long, and the pressure delta between sides is about equal, plus the standing wave from the individual cylinder power pulses will just about stop any significant cross flow.

 

U.S. bikes came with a hose between the vacuum ports as that was to equalize the purge process between TBI’s. It worked for that application because during the evap purge there was tee’d flow into the hose from an outside the engine source so a rather large pressure delta.

 

If you want to make an effective equalizer between sides you will first need to drill the TBI nipples out as large as possible, then make reducers and run a crossover hose of about ½”-5/8” ID. I have tried that on a couple of old 1100’s and it still didn’t make enough difference to justify all the work.

 

[rustyfingerz]

 

 

Well, I'll leave well enough alone.

Its been raining all day hear on the coast.damn

guess that cigar n me will get together with a drink and watch the race. Thanks for your help dirtrider.

ride safe.

Mark

[philbytx]

That'll teach you to use that damn Frog electickery contraption instead of the good old British Morgan Carbtune .

 

First time it's hard...it gets way easier now

[AndyS]

That'll teach you to use that damn Frog electickery contraption instead of the good old British Morgan Carbtune .

 

First time it's hard...it gets way easier now

 

Amen brother!

[rustyfingerz]

Ha, I got time, this week I"ll hook up the home made manometer see if I can

complicate things a little.