noise?

mine was fouled yesterday, cleaned the oild off, its still blackend to a crisp, kinda like the pre ignition, need to fix, should i rejet, with winter coming to an end i might ride the bayou220 so i don't have to jet, then rejet when ithets warmer in 2 weeks, haha, but would it be too lean if its fouling with detonation or pre ignition???
 
i'm not osing any performance from this, anybody know, wat size jet should i use to rejet it??? tomignt its 31 degrees out here so it isn't super cold, compared to the - temps some of you get, so how should i jet it, and do you think there is anydamage done to the engine, i rode for 1 and a half hours yesterday, and a couple short rides over school break
 
also, it sounds alright too, like any other blaster, just a weird noise, still,i need to get plugs and rejet, what shpuld i do to rejet, just turn the jets a few turns out/in? or put a new one in that is bigger/smaller?
 
havn't done the timing yet, i need to rejet still, so dik, migh just be a bolt rattleing too, i lost no performance, it runs the same temps it did before, what size jet should i use to rejet for winter, smaller or bigger? like do you jet leaner or ricker for winter?????
 
I thought we had this pegged by the first posts....I had an experience with a marble, rattle symptom constantly...only when I was coasting tho...all it was is my chain wore through the guide and the carrier guard, cuz it was prob'ly hit and is bent all to sh.t...so until I had someone just to ride it pass me with the engine off I figured it out...when I took off the guard it stopped making the noise, ....so ya what you're describing sounds like what I had....
 
i as lookin, the front of my aftermarket skidplate was all eaten to crap, and the swingarm guid looks ok, it has a new skid plate guard, so now what i;m gonna do is have my dad pull the blaster with his bayou and let off the gas let me coast and see what happens but that might not happen soon though, how th plugs look? those were cell phine pics sorry, but i need to do somthing with the skid plate, it is so close to the chain that it comnstantly hist and he chain has to go up to get past te rubber peice that keeps the chain off the skid plate, i think this is my prob, what should i do with the skids, they looks ok, i had them off not to long ago, so what now????
 
I want to compare with my latest pics...which one looks the closest to yours.
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i figured out what the pug prob was, i wasn't letting it warm up enough, that is what the yamaha mechanic said, i'm gonna run a BR9ES spark plug instead of a BR8ES, should work better the guy said, i'm gonna have to do some skid plate modding when the times right, thanx guys prob solved, the noise was the skid plate, the whole front of it was chewed up, i need to tighten the chain, or get a new one.