r-chri12
08-16-2010, 07:11 AM
just bought this 1993 ex300 ,starts and idles fine. idle to around 1/4 throttle bucks and jerks on moderate to hard accell. has a cobra exhaust system and k&n air filter I think the engine is stock.spark looked weak put in a new spark plug and coil,spark still looks weak,possible cdi box? there are two boxs on the frame front left side,one is about 3 in,s long with 2 plugs the other one is smaller with 2 plugs and a pigtail which one is the cdi box (ordered a service manual but have,nt received it yet) I have adusted the needle jet one notch at a time this does not seem to change the problem I also ck,d and adjusted valve clearance in .004-ex .005 everything I have done seems not to effect the problem good or bad any advice would be appreciated .thanks.RC