I didn't have enough slack in the timing chain to get it over the cam gear. The chain tensioner is not the problem. I have removed the head and jug. The chain feels like it may be caught up on something in the crank. Could that be possible?
Lift the chain with one finger then turn the crankshaft several full turns by hand. Inspect the full length of the chain during rotation. Any obvious damage? Does the chain revolve smoothly around your finger? If all seems okay then the problem is probably not in the lower end. Some chains are continuous and do not have a master link. Some do have a master link. If you have a master link then separate the chain by removing the link then place both ends of the chain onto the cam sprocket and reconnect the link. If you have a continuous chain I would need to see first hand what is going on. In any event, be certain the timing marks on the flywheel and overhead cam are correctly lined up during installation.
Hi mate didn't get any info on what bike you are timing but this procedure is simular for most and is specific for WR YZ 250 426 and 450
set piston to TDC (top dead centre)
this can be done by spinning the fly around until you can see the (i) mark
stamped on the flywheel line up with the marks on the inspection plug hole
(engine case) good idea to probe the cylinder through the spark plug hole to
confirm the flywheel mark is correct (I have seen several 426) where the TDC
mark does not give accurate TDC on piston so worth second guessing this
process.
once TDC is set do not allow piston to
move from this point on - starting with the exhaust cam with no slack on the
cam chain the dot stamped on the cam sprocket should align with the face of
head with the cam lobes pointing outward roughly 45 degrees towards the front
wheel when this in place
you do the same with intake cam except
the cam lobe will face opposite direction outward and the should be a dot
aligning to the head
double check before you go further that
when you put your finger in the chain tension hole and you tension the cam
chain that when all slack is taken from the cam chain that your dots on both
cams align with head face and that you still have piston at TDC if all checks
out then this is timed set correct so torque all the cam caps back up install
chain tensioner and the recheck all fly wheel marks are in correct position and
piston is at TDC and the dot on each cam sprocket aligns to the head if it
doesn't then re do the process
don't be surprised if this takes a few
attempts as it takes the best of us usually at least two attempts to get all
marks to align correctly thats why best to check and double check before you
bolt it all down then you can adjust just by lifting one cam out and moving one
tooth either direction
You have little room to play with and
when you start putting chain on the cam sprockets you will find very little
extra chain length to play with you may need to wiggle tug and pull both cams
together to get them back in each time but go slow and gentle they do go in
they just need to be encouraged
I happy to elaborate on any point if
you need - good luck
Regards Jamie
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2001 has bike got Manuel timing chain tension adjustment
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