k i just bought the bike with some problems and i have been diagnosing in my spare time (wich isnt much) first.. valve chatter and side engine chater on first start. first problem solved with a manual cam chain tensioner. the next is a little more tricky to describe.. but here it goes.. if i slowly open the trottle it sounds like im misfiring and a lot of engine vibration.. but once i rev it up or open throttle when im riding it pulls smooth and hard. wheel up without clutching infirst. but as i decelerate or meet my speed with throttle it has the same rough chop..
things i have done to investigate. went through air fuel mixter needles one by one. closing them off and opening them slowly to see if i could find a better setting... the two left cyl. are tuned nice,,, but the two on the right are not firing at all. they have spark and the pluggs are clean light golden brown... oil on the threads of the pluggs however so it sounds like da da da da zrooooommmm. when i rev it. even if i hold it at 8000 rpm it will be da da da da. until i open throttle fastagain. then i get a real nice zroooooommmm. smooth and even..?

what to do?

 

oh yeah forgot to metion that all 4 seem to combust when revving,, how else could i get up in farst without clutching it... second and third with only a hint of clutch.. it pulls like it should.

 

let it run at an idle without revving it up. Then pull the plugs on the cylinders that aren't running. If the plugs aren't wet then something is probably gummed up in the carbs keeping gas from getting to the cylinder until you open it wide open. If they are wet then a float needle or something is probably hung up or something because its dumping too much gas in. You said you had good spark so there probably isn't too much need to troubleshoot that.

 

I'm with Elmer, your symptoms point to carb problems, most likely idle circuits. [8D]