TB balance weirdness..

[Andre1150]

after a major repair (renewing stripped input shaft), I repaired a rattling right side throttle body with Dan Cata's kit. Ok, on to sync.. I loosened all knurled nuts and reset each throttle body BBS to 1.5 turns out. basically, starting with the butterflies on the stops, and each Bbs 1.5 turns out as a baseline. I then started the engine.

 

my twinmax shows a consistent bounce between right and left cylinders. however, if I give it throttle, the twinmax goes all the way right and stays there throughout the throttle. I.gradually tighten up the left side throttle k nut trying to equalize them.. but I can nearly tighten the left side so much.that the butterfly is wide open. so now the butterfly is off the stop at idle, and upon throttle, the twinmax shows vacuum still pulling more heavily" the right, just not as much. changing the bbs or cranking down on the left side TB.screw, I still have a large pull on the right, weak on the left. no matter what I.do, I can't seem to balance the throttles, even following the advice on WIsdom which details a full walkthru.. any ideas?

 

[dirtrider]

Afternoon FireKit

 

I'm not sure what you have there BUT vacuum is deceiving.

 

The more you OPEN a throttle plate the LOWER the vacuum is (just opposite of what most think)

 

In any case start over-- re-set the BBS to 1.5 turns out then back the cables off until BOTH side throttle cams are sitting solidly on the stop screws.

 

NOW start adjusting the cables until you can feel both side TB cams lift of their stop screws at the same time (or as close as possible) but still have the TB cams solidly on the stop screws at rest. Then verify that both sides hit the wide open stops at the very same time.

 

Once the above is done THEN put the TwinMax on & do your final adjustments (shouldn't take much if the above preliminary was done correctly.

[Andre1150]

or, do I.have a huge air leak or a more open throttle plate on the left side because I was fiddling with the knobs?. I'll start over.. but wow the bike is running and shaking like an agitated pony.

[dirtrider]

or, do I.have a huge air leak or a more open throttle plate on the left side because I was fiddling with the knobs?. I'll start over.. but wow the bike is running and shaking like an agitated pony.

 

Evening FireKit

 

If the idle balance was fairly close with the BBS at 1.5 out ( & TB cams on the idle stop screws) then you don't have a large air leak.