Mikuni VM34 Question???

[xscessivecompulsive]

Hey guys, quick question. So yesterday I intstalled my Mikuni VM34's and have been taking it for a few runs around the block! I notice that when I let off the throttle to shift it maintains a constant RPM. Almost like its on auto pilot, and sometimes if Im at a stop sign and give it a quick blip on the throttle it revs fairly high and maintains that position! Its almost like the throttle is sticking but I know thats not the case! Any of you guys have any explanation as to what might be going on here! Its really close to being right on, and roadworthy!!

Thanks in Advance.

XsC

 

[Captmilk]

I'm no carb master. But After adjusting the cable tension and Idol screw, you should get the results you want. Look in the carb tuning book that came with your VM34's it's got tons of good advice.

 

[racerdave]

It never comes back to idle, or just takes longer than it should?

 

[grizld1]

If in fact the throttle isn't sticking, and if in fact the engine idles down after startup, and if in fact your problem is not being caused by failure of an early mechanical advance unit to return to retarded mode when rpm's drop, then you're looking at one of two things.
1. Air leak (at vacuum barbs if present, or between motor and carb mount) opens at full warm-up.
2. Mixture screw setting is too lean.

 

[thrashin]

You need to tune them, jets may need changed out or you may have to adjust the needle.

Start by making sure they are synced and the throttle cables pull the slides t the same time. Know which screw does what. The small flathead screw on the air filter side of the carb is your air adj. Screw it in all of the way. Not to tight though, then back them out a 1/2 turn. Try sum throttle. Then repeat another 1/2 turn out and throttle. If you get past 2 full turns you'll probably be looking at different jets.

This assuming that you have; adjusted the cam chain and set the valve tappet clearence.

 

[ProSimex]

open up the advance cover and see if the advance mechanism snaps back closed when you flip em open. if not then remove the springs, heat em up and squeeze em tight with some needle nose pliers. put em back on and it should be good.


or your carbs are the problem

 

[Take Warning15]

If you heat the springs won't they break instead of stretch after they are cool?

 

[ProSimex]

so everyone has told me, mine seem to be just fine