Armando Posted June 1, 2011 Share Posted June 1, 2011 Doing TBS and there is 1 full turn difference between BBS'. How do I get them closer to one another? Also, upon acceleration, the LH side gauge of the manometer rises faster than the RH but does eventually settle about close to the other. What does this me? Thanks Link to comment
AndyS Posted June 1, 2011 Share Posted June 1, 2011 Get some Catalytic converter compatible carb cleaner. Remover the BBS's and spray the galleries that they screw into. Give the TB's as good a clean as you can. The tiny holes that lead to the BBS get filled with deposits which effectively alter the size of the hole (replicating screw adjustments). So get those little holes really clean and you should be good to go. Andy Link to comment
dirtrider Posted June 1, 2011 Share Posted June 1, 2011 Afternoon Armando First off, are all you valves set correctly? If not start with those as valves out of adjustment more than just a skosh can have an effect on TB balance. If the valves are in order then do Andy’s suggestion above as a starting point. On the other question you have: “upon acceleration, the LH side gauge of the manometer rises faster than the RH but does eventually settle about close to the other”--- That would depend on how far it is off and the viscosity of the fluid being used. If you are using something in you manometer that is light and thin like water then you will probably get one side to have a bit more gain than the other side. A couple of inches of water in pretty darn slight when comparing to inches of mercury. The difference could be as easy as one side having a larger diameter hole in the TB nipple due to crud or dirt. Of one hose on your manometer being kinked or different than the other side. If all is equal on the vacuum path between the TB nipple & manometer then look for things like coked TB throttle bores, or worn TB bushings or throttle plate shafts that are worn, or throttle cables that don’t seat or ride the same in the TB cams , or one TB opening slightly ahead of the other for some reason. If nothing found in the cables or TB’s then possibly a slight exhaust restriction on one side, or coked valve stems at rear of valve head, or exhaust reversion, or intake flow disruption, or?????. If just a bit of H2o height difference on no-load throttle-up then I wouldn’t worry about it too much. Steady throttle is where you will feel it the most if at all. Link to comment
Armando Posted June 2, 2011 Author Share Posted June 2, 2011 AndyS, D.R. and Spyder: Well, here is what I found: - put carb cleaner on both TBs. Quite a bit of fairly black fluid came out of the LHS nipple. Idle is back to normal. However, - when doing the tbs and getting the tbs in line, they would get out of balance after thightening the adjustment nut. To make the long story short, I found that the RH adjustment cable adjuster was stripped. Put things to rest until I get the replacement. Thanks for the help. Link to comment
SKYGZR Posted June 2, 2011 Share Posted June 2, 2011 Soaking a Q-Tip with the carb cleaner and swabbing the BBS bore will also remove more than you realize..(evidenced by how black the Q-Tip gets).. Link to comment
Armando Posted June 2, 2011 Author Share Posted June 2, 2011 SKYGZR, i used the qtip soaked up with alcohol. took 2 of them on each side to before coming up clean. I must have pushed some of the crud in to the point where it was no longer possible to get to it with the qtip. The carb cleaner definitely got more out. I had the clear hose from the manometer still attached to the vacum nipple and about 2 inches of black fluid got into the LH hose. a Link to comment
legarem Posted June 2, 2011 Share Posted June 2, 2011 After doing all the peoples mentionned above, I had the same problem and my vacuum was unstable between the TB after many adjustment sessions. To try to get rid of this problem, both BBS were adjusted the same and after I adjusted the right TB vacuum with the TB stop screw. I had to fine tune with 1/8 of a turn the right BBS to be ok. Bike is running great. Stable idle, not a hint of surge. Link to comment
AndyS Posted June 2, 2011 Share Posted June 2, 2011 I would advise against using the throttle stop screw until everything else is set up. It is after all a stop screw and this isn't in play at higher RPM's. I think Armando has identified his problem with the adjuster screw being shot. Andy Link to comment
Armando Posted June 2, 2011 Author Share Posted June 2, 2011 I will be replacing the rh bowden cable first. I suspect this will get me back in balance. After that, it would be nice to get the bbs screws back in line with one another but as long as it idles good, I will probably leave as is. I am however, curious as to whether the stop screw is the right way to get the bbs screws back in sync. Link to comment
Boffin Posted June 2, 2011 Share Posted June 2, 2011 I will be replacing the rh bowden cable first. I suspect this will get me back in balance. After that, it would be nice to get the bbs screws back in line with one another but as long as it idles good, I will probably leave as is. I am however, curious as to whether the stop screw is the right way to get the bbs screws back in sync. The stop screw are set up at factory on an airflow bench and then locked with varnish. They should not be touched except in dire emergency. The BBS are adjusters to compensate for differences in throttles. If they are a long way out it is usually down to a worn butterfly shaft. Bing make and sell rebuild kits. The kits do not have a new bush but these are available from McMaster Carr or similar. Andy Link to comment
legarem Posted June 3, 2011 Share Posted June 3, 2011 As many notified, the right stop screw in my RT (never touch the left one) had to be adjusted to get correct BBS settting on both TBs As specified, this is the last thing to do after ALL was tried. This cured the TB imbalance on my bike. Every time I adjusted the BBS to get the same vacuum on both TBs, it it was ok a short time but always changed soon in imbalance. When I opened the throttle, The vacuum balance was never ok when returning at idle. I readjusted it more than 10 times and became tired. I decided to try the TB stop screw when I read this procedure. http://isatis.mecanique.free.fr/R1100_RT/Allumage/p1.htm Link to comment
Armando Posted June 3, 2011 Author Share Posted June 3, 2011 Now I have a reason to learn french! Link to comment
hootowl Posted June 3, 2011 Share Posted June 3, 2011 If they are a long way out it is usually down to a worn butterfly shaft. Bing make and sell rebuild kits. The kits do not have a new bush but these are available from McMaster Carr or similar. Andy Rebuild kits with bushings and instructions can be found here: http://advrider.com/forums/showthread.php?t=630335 Link to comment
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