Timing a 400ex

[tyman2395]

Hey guys since all my parts are on there way how do you time a bike?

[dariusld]

Ignition timing?

[tyman2395]

ya how many different timing thing is there?

[scuzz]

Originally posted by tyman2395
ya how many different timing thing is there?


Maybe lap timing? Or timing your riding during your girlfriend/wife/significant other's monthly cycle....who knows.

[tyman2395]

i mean like timing the motor

[tyman2395]

k guys heres what i need to know once i get my motor back together what do i have to do? adjust the valves and what else?

[Pipeless416]

alright heres the quick version. your engine should be at tdc when you start. while holding up the cam chain, put the cam gear in it. there are 3 lines on the gear that are facing the outside. line these lines up with the top of the head. after it is lined up with the chain pulled tight, put the cam in with the lobes facing down, and bolt in using locktite. you are now in time! :) heres a rough picture of how it would look.:)

[tyman2395]

thanks pipeless now i got a pretty good understanding of it it looks fairly easy

[dariusld]

That wasn't your question. If you want good answers, ask the right way.


Originally posted by tyman2395
once i get my motor back together

[motoboy66]

Originally posted by Pipeless416
alright heres the quick version. your engine should be at tdc when you start. while holding up the cam chain, put the cam gear in it. there are 3 lines on the gear that are facing the outside. line these lines up with the top of the head. after it is lined up with the chain pulled tight, put the cam in with the lobes facing down, and bolt in using locktite. you are now in time! :) heres a rough picture of how it would look.:)

Pretty good, but you forgot to talk about the "T" mark on the flywheel. Take the 2 plugs off the engine on the flywheel side, turn the crank, 17mm, counter clockwise until the "T" mark is in line with the case marking in the hole the little plug came out of.

[Pipeless416]

Originally posted by motoboy66
Pretty good, but you forgot to talk about the "T" mark on the flywheel. Take the 2 plugs off the engine on the flywheel side, turn the crank, 17mm, counter clockwise until the "T" mark is in line with the case marking in the hole the little plug came out of.

hence the reason i said it needs to be at TDC.

[tyman2395]

when i do this should i also adjust the valves?

[lilyamaharacer4]

Yes mine wouldnt start after its rebuild until we adjusted the valves. You will probably also have to adjust the valves after break in.

[RaceinCircles]

My quad has had a knocking noise ever since my rebuild, which we ziptied the cam chain so it wouldn't fall in the case or move. My clearances are correct and there is still a loud tick...could this mean that my timing could be off a few teeth?