TOPIC:

Took carbs apart for cleaning, when I got them back together, the choke butterflies on 1&2 are sticking pretty bad. I checked their mounting on the racks to see if they were binding the rod that holds them, but with no conclusive results. If I tap on the side of the carb, it will eventually shut. Question is, will the vacuum from the engine pull these shut while trying to start or do I need to take apart again and check for absolute straightness?

Post edited by: Wirewulf, at: 2007/04/17 13:47

Never saw a VM carb with a butterfly. Saw Keihin CV34s with choke and throttle butterflies. Have seen the choke butterflies stick.

First, try spraying some WD40 into the wells where the ends of the choke pivot rods sit.

Second, make sure that if you took the butterflies off and put them back in, you did it correctly.

Third loosen the rack bracket mount bolts... the big 6mm bolts and retighten and see if the binding goes away... you might want to try tightening in a different order than the original one you used.

Last, if those things didn't work, you probably have a slightly bent mount bracket. Take them both off and make sure they are true.

My bad, it is Monday, and my head's all full of cold medicine! You're right George, as per usual.

Tried the WD40 thing. no workie.
I double checked the installation, and from my figuring they will only go in and actually move one way.
I'm afraid you're onto it with the mounting bracket.

I'll get back into it and see if I can't figure it out. Thanks for the direction. I thought you'd probably seen this before.
Thanks

I had a similar problem, turns out one of the clamps that hold the carbs to the intake manifold was turned and binding on the throttle linkage and would stick at WOT when I twisted the throttle grip!

RRRR, I took him to mean that the binding was occuring with the carbs off the bike. The throttle won't move if the 5mm screw in the clamp sits at an angle and contacts the bellcrank. I replace the clamp screws routinely and if the one on the #2 carb is a little long this can happen but I just loosen and rotate. The others could hit the sync mechanisms if they are rotated quite a bit.

I see the problem with the butterflies all the time... I usually don't have a problem with dirt since I clean the innards of the surface the shafts ride in. Occassionally, if they are just a shade sticky, I can WD40 and loosen/retighten the rack bracket bolts. If that doesn't work, next step is to check to ensure the bracket isn't bent. If it is straight, you may have to disassemble and clean the surfaces where the pivot shafts pivot and if that doesn't work, take out all four of the butterflies and make sure they are straight and there are no burrs on the edges... the edges can be polished for a better fit.

You're right on WG, carbs are still off. I'll update you once I've addressed the problem again, but I'm warning you, the wheels of action turn pretty slowly in the shop these days!