Motorcycle Repair: Yamaha Maxim 700x, shades of brown, nut shell


Question
1985 maxim, did run great until i stupidly took baffle cover plates off, now everything has gone to poop. I tried putting plates back on, didn't help matters. I hear a tamboreen now when i ride, constantly, but it's not the baffle plate that rattles it's inside of engine. it doesn't like to start anymore whereas before it never failed to start! it seems hard to keep running when stopping, i have to continuously hit the throttle to keep the rpm's up enough so it won't die. adjusting idle does not help at all. it now makes a hard sound when i shift(shifts easily no problem with clutch i don't think) its like dropping a piece of metal on a hardwood floor, same sound and thud! not half the power it used to have, and it seems to cough when im ridin 50mph or better hesitates like not enough gas but i don't think thats the problem, maybe timing? i don't have a clue how to adjust but willing to learn! someone said maybe it's time to upgrade, i say no way i love this bike and i want to fix it badly! please help!

Answer
Hi Lynette,

Was the MC stored awhile and recently brought out of storage? Do you know of any repair or maintenance history?

First thing to check is the spark plugs. Remove them and see if they are fouled. You want to have the center porcelin color in shades of brown. If they're white, well that's ok, but best to be a bit darker. In a nut shell, black an sooty means carb's air-fuel mix is too rich and needs tuning. If they are white and speckled as if peppered, carbs are too lean and tuning is necessary. Clean or replace the spark plugs and retry starting.

Describe the appearance of the plugs to me and what hapened after trying the above. We'll go from there. Use my email for replies: mshively1@woh.rr.com

P.S. Yes, I agree with you... keep the Maxim!!!

Respectfully,
Mark Shively
Dayton, Ohio