my 2002 400ex just wont start but wants to

i just got a 2002 400ex and..................

when i try to start it, it tries to start and stops tries to start and stops tries to start and stops over and over, like it has the hiccups, but wont start and run. the carb is clean and it's getting gas to the engine, the spark plug is sparking a blue spark when i hold the plug to the frame. ive put a new timing chain and stock cam shaft in it, and set the timing, and it has a new piston. anybody know the problem??


thanks

sounds like a timing issue to me... might check the chain tensioner too...

the timing is correct. as far as the chain its very tight can that be a problem??

ok thanks

Did you get this fixed?

there are 3 basic principles for diognostic
spark/fue/compression
you have ther first 2 now check compression and leak down
that will tell you if the piston is too small for cylinder/need boring
or valve train has a problem
the reading can also signify timing issues

THANKS to EVERYONE for the help its in the local shops hands now i dont have a filler gauge to adjust the valves and i did not want to send a valve through the piston from bad timing. the shop can get me running right.

Originally Posted by yamahabansheeboy THANKS to EVERYONE for the help its in the local shops hands now i dont have a filler gauge to adjust the valves and i did not want to send a valve through the piston from bad timing. the shop can get me running right.

Cool, let us know how it goes and what the issue was.

ok will do thanks to all again =)

quad still in shop SLOW ass people! im about to