YTM200e backfiring through carb wont start?

[kylecoyote]

I picked up a ytm200e a week ago been trying to get it going. Had to replace the driveshaft gears. Pulled the carb and cleaned and blew everything out. It will turn over fine but won't start. It spits back throught the carb or out the tail pipe. I checked the timing marks. The T is lined up when the cam is lined up on the compression stroke( thumb over spark plug hole). So what do you guys think? Thanks for any help this site rocks.

[fabiodriven]

The valves could need adjusting. If the intake valve is staying open more than it should it would backfire right through the intake.

[kylecoyote]

I checked the clearance per the manual. If anything its a thousanth or two loose on both the intake and exhaust.

[mrmello]

Did you pull off the cam chain cover to make sure that the sprocket mark lines up at TDC?

[kylecoyote]

Yea thats how I checked the cam lining up.

[Palehorse]

I have the same issue, my dad bought the bike used in 85 and I've had it ever since. It sat in his shed for a few years and I just brought it home, cleaned the gas tank, pulled the carb off, soaked all the parts in an ultrasonic fuel injector cleaner, sprayed it down with 2+2, blew t out with air, still have the same problem. The carb is spotless, timing is right on, just will not idle. Now I'm looking for a rebuild kit for the carb

[Palehorse]

Guess who had the float in upside-down.... This guy. I feel like an idiot!

[muthey]

my guess is it is dealing with the carb, also check for a crack or leak in your intake boots. how wet is your plug when you pull it after trying to start it. Are you flooding out, might even be running into the air filter and filling it up. How good is the spark plug is it new? try pull starting it behind a vehicle, and see if it runs. Is your choke stuck? There are alot of things to rule out before we can get down to the nitty gritty of it.