Backfire when trying to start 400ex?

For some reason the timing chain had came off on my quad. Put that back on, and also replaced the head gasket. Got everything in time, all 3 marks on the cam line up with the T on the crankshaft.

When I go to start it, it just backfires and it will not start. Please help!

Have spark and plenty of gas.

I have a 2001 400ex with the 440 big bore kit, wb racing cam, ct racing pipes & headers, K&N filter and jet kit.


Daren

[B@ckBoneBelgium]

did you look if your valves wher still straight and closing perfectly ? Check also your clearance between rocker and valve !

I think your valves are not straigt anymore ...
:o