bike wont start after carb clean '08 YZ450


I recently cleaned my carb and now the bike will not idle and only starts if I crack the throttle a little. The bike fired up first kick cold before any maintenance.

All jets, needles and positions are stock except for a 165 main.

FMF powercore with powerbomb header

Fuel screw 2 1/4 turns

I messed around with the fuel screw, moving to 2, 2 1/2 then to 2 3/4. I also tried many other variations.

I think I flooded it trying to kick it so many times. I also noticed some fluid coming from the front of the head gasket and also the next gasket down. I guess that is the cylinder gasket. That kind of freaked me out and I stopped even trying to start it after seeing that.

While the carb was off I checked the hot start plunger and it was functioning fine.

At the track, someone said it smelled like old gas. The gas was really only a few weeks old and there was not much in the tank when I mixed it with fresh gas.

I didn't think the plug had fouled since I could still start it with a cracked throttle.


Where's your idle set? Also I run all my bikes af screw at 1 and a half

Edited by chris856

I think I figured it out. It appeared that there was a leak at the gaskets, but the fluid actually just ran down where the pipe connects to the head. Apparently you can't fix stupid.

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