2007 yfz 450. can you help????

[mikekingadams]

ok, i have a yfz 450 and up until about a month ago it ran great. it has a yoshimira exaust system and stage 2 jet. it was a beast. it started to leak oil from the top of the crankcase cover. so i took off the crankcase and put a new gasket on. the bike now runs like crap. it needs a new cylinoid, i get no response from the electric starter. the cylinoid buzzes when i try to start it. ok, but the real problem is in the timing. (i think) when i push start the bike it sputters. feels like the fuel air mixture is wrong, or its not firing on time.it is a sputter in the engine. it doesnt pop or crack from the exaust, its somthing in the motor. i dont understand what could of happened. could it be because the cylinoid is bad? its not completeing the circut? i dont have the money to take it to a shop right now. i do have the tools to fix it. i just dont have the experience to diagnos the problem. any advise would be greatly appreciated.

[Big Red]

I'm no mechanic, so don't mark my words in stone and I'm also not sure exactly what was done on the bike before the issue started. Was the the seal between the crankcase and the cylinder? Or was it the seal between the cylinder and the cylinder head (valve cover). If it was the seal between the valve cover and the cylinder and you didn't actually have to mess with the timing chain, then I wouldn't think it's a timing issue. If it's the seal between the cylinder and the crank case....might be a different story. Give more details/clarity to exactly what you did in repairs and I'm sure someone on ATM will be able to give you more informed advice than I can.

[mikekingadams]

ok no prob. the only part i took off was the crankcase cover. i never touched a timing chain. it had the magneto on the inside of the crankcase cover. i had to take my gear shifter off to take off the crankcase cover. all i did was replace the gasket. never came close to the valves. altho a friend told me on his raptor, that his was doing somthing similar and it needed a valve adjustment. but i just bought it in april, and the weather hasnt changed really. so i dont think its the valves. i mean, it feels like its not sucking fuel right. like its not sucking enough fuel. or the timing. is it possible to jump time like that?? it seems like a long shot. maybe the fuel air mixture is wrong. ive never adjusted anything on the 4wheeler. it ran fine for over 3 months. i noticed it was leaking oil, so i brought it home and parked it in the garage. it sat for a few weeks. i replaced the gasket and now it sputters. thats really the best desripton i can give. sputter is the best word to desribe what it does. it needs to be takin to the shop, but i just dont have the extra money right now. like i said, the cylinoid is bad and the elctric start doesnt get any response. could that be part of the problem??? thank you for your help...

[mikekingadams]

i fixed it. it was in the carberater. jet was clogged. runs great now.