i just started my 250 for like the 2 time sceince i rejeted it ..... and i was crouchin down by the motor and it smelt like something was burning.....the plug was fine..... could it be that the new jets just have to break in or maby i havent ridden in so long that i cant remember what it smells like???? did eny else notice this when they rejeted????... i whent up a size in both jets and would that mean its runnin lean or rich?????... actually it might be the air filter... i just cleaned it with special spray that i bought at my local motor sports shop could it be that the stuf is being sucked into the motor and thats the smell thsat the fumes are goin in with the air????.....P.S i washed the filter out afret i sprayed and let it sit.

the larger the number on the jet ,the larger the jet is, which means more fuel flow, so if you went up a size it should have increase fuel flow, as to your airfilter, you should have spayed the cleaner on , then take water and wash the filter out, sometimes you need to do this a couple of times depending how dirty the filter is, let dry, reoil the filter, reinstall