400ex problems

[Eddie_552]

i have a 2002 honda 400ex, i rebuilt the top end and had issues for weeks not realizing that i had lost the decompression spring and plunger. i finally got new parts and got it back together. it ran great... i took it out for a good solid run rather than just running it in the garage, i made it a good half an hour or so before there was a loud almost knocking noise then it suddenly died, after 15 minutes or so it started right up with no knocking or anything so i thought we would work our way back toward camp, after a few minutes it did the same thing, i might have made it a mile, after it cooled down i got it to start again and then i made it back to the truck... after getting it home i tried starting it and it cranks over and sounds like it wants to start but wont kick over, i re lashed the valves, double checked the timing, checked for fuel and spark... i got it to start once but it just did that same knocking noise while idling and i was afraid to rev it or anything then it died after a minute and i cant get it to start again.

[jerod400ex]

Timing chain and tensioner all good? Did you double check when u put the rings in that u put them in the right way? Correct spacing from each other and all of that?

[Eddie_552]

Yeah I replaced the timing chain and tensioner, I double checked them when I tore into it the other day, im pretty certain that the rings were on the right way I double and triple check myself when I'm that deep into a motor.

[jerod400ex]

Does the knock sound like it's in the top end or bottom end??

[Eddie_552]

It sounds like a top end knock to me but I guess I could be wrong.