trajiks9, thanks for the offer, but i've got to work on my truck and my buddy's bike this weekend.

My thwack at idle relates to my transmission/clutch because if i pull in my clutch the thwacking goes away. I also get the surging idle as Trajiks9 described.

 

That could be clutch basket springs then.

 

as in clutch pressure springs or am i missing another set of springs specifically for the basket? I did a clutch job in the off season and replaced the pressure springs, so that shouldn't be the issue.

 

Those were the ones I was thinking of - when they get loose they allow the clutch to clatter. Still could be clutch related - but if you replaced all of the plates I can't think of any other wear item.

 

well, i need to re-do my clutch this off-season (the pads i got are garbage anyways). do you know anything about the clutch judder spring? I remember that fell out on me before i got a look at how it was positioned, and i *believe* i got it back in properly by looking at diagrams. also, i didn't put thread lock on the spring bolts so they may very well be an issue.

back to the main topic! trajik and i seem to have a bouncing rpm, and i'd like to know what sensors (nobody say ecm, please) control or have any bearing in rpm calculation or fuel load. I'm thinking MAP, maybe a cam position sensor, maybe a funky injector? any ideas?

 

i wonder if you guys are having the same noise i am mine only seems to do it in first gear with the clutch let out. its noticeable when im rolling at idle but worse if its free spinning on the rear stand. its just a sporadic slap that occurs every few seconds or every 10 seconds its really weird but it jolts my whole bike. does that sound familiar?

 

also unbalanced carbs can make for a seriously rough running motor, esp if they are off alot...