400ex problems

[iowaexer]

i recently put back together my 400ex motor and now it won't start.It is turning over but it doesn't sound like it did before. It almost sounds as if there is a lot of air being moved through the air filter. Any suggestions or ideas on what the problem might be? thanks

[drew416ex]

Sounds like maybe your timing is off or the valves arnt adjusted properly.

[BigBore24]

Originally posted by drew416ex
Sounds like maybe your timing is off or the valves arnt adjusted properly.

I agree. try taking the boot off the carb and hold your hand over it. does it blow or suck your hand? if it blows your out of time

[iowaexer]

I just checked it out and it was blowing.I did a process that i got off of the internet to time it and that didn't work. Do any of you know how to time a 400ex properly? Thanks

[lorenjr83]

where you at in iowa

[drew416ex]

with the valve cover off there are two lines on the cam sprocket. The lobes should be facing down and the two lines should be parallel with the top of the head. There is a small plug on the left case cover. remove it and there is a mark on the flywheel with a "t" on it. like the T mark up with the mark in the case cover.

[iowaexer]

yes i am located in iowa.......i did that process that you are talking about, i guess i might have done something wrong