cant get my 02 400ex running help.

[hotrod402]

hey guys im new to exriders and just got my quad not to long ago. about 2 weeks ago quad was running great and started right up but i noticed the head gasket was leaking so i took it apart to replace the gasket. Well i just got the quad bak together and now it doesnt want to start. the thing is tho i am jumping it cuz the battery is dead. Also from time to time it will start up for about 2 seconds and die. any help would help guys thanks.

[01boneless]

sounds like timming is off .

[eprovenzano]

I agree, timing is off

[DirtyBirdRacing]

I have made the mistake of leaving the gas off or the kill switch on... maybe check those?

[CJM]

The stock cam, did you put back on the decompression mechanism? Its a small pin and spring, without them it wont start no matter what.

[hotrod402]

no i dont think it is a stock cam, someone looked it and said it looks like a hot cam cuase of the color of the cam but the only marking i see on it is a H and an, A on one side. and also i did look for the sring and pin when i first took apart and it wasnt in so my guess is it is a aftermarket cam. I did the timing twice cuz the first time i did it i did set it to tdc and set the cam loobs down. Tryed to run it and wouldnt start then i took apart again and seen the timing was off so reset it to tdc again set the cam loobs down. tryed to start it and it ran for about 3 secs and shut off. My other question is would it be because the little screw in the middle of the tensioner is not in? my buddy misplaced the screw and said it wouldnt matter if its in or not.

Would that make it keep jumping timing?

[hotrod402]

no i dont think it is a stock cam, someone looked it and said it looks like a hot cam cuase of the color of the cam but the only marking i see on it is a H and an, A on one side. and also i did look for the sring and pin when i first took apart and it wasnt in so my guess is it is a aftermarket cam. I did the timing twice cuz the first time i did it i did set it to tdc and set the cam loobs down. Tryed to run it and wouldnt start then i took apart again and seen the timing was off so reset it to tdc again set the cam loobs down. tryed to start it and it ran for about 3 secs and shut off. My other question is would it be because the little screw in the middle of the tensioner is not in? my buddy misplaced the screw and said it wouldnt matter if its in or not.

Would that make it keep jumping timing?

[01boneless]

i dont think so it but it may?

[eprovenzano]

The screw in the tensioner is just a cover, it should not effect anything.

[hotrod402]

ok ill try to reset the timing again tomorrrow and ill see what happends thanks guys

[hocman123]

my money is on the tensioner is bad did u check to see if the thing springs back and how tight is the chain on the cam after u put tension on it? there should be little to no wiggle in the chain.

also the cap will not effect timing but oil will shot out of that hole when running and squirt a nice amount out in a vary small amount of time so u cant go for a long ride untill u get a cap on it. i think u can guess how i found out about that :)

[howie14]

my friends did the same thing after rebuild it was the rockers we found out that every time you take the topend apart you have to ajust the rockers cause otherwise the exaust valves hang open on the compression stroke witch means it wont run or will run real bad