Motorcycle Repair: rm 125, piston rings, rod bearing

Question
hi wayne
i have an 2001 rm 125 and i was riding and then suddenly it started to bog down and it will start for a few seconds but then it shuts off when i kick start it it makes an odd clacking noise if u have any ideas let me know asap please  sincerely  
blake price

Answer
Hi Blake,

It sounds like top end engine trouble.
It may have had a partial piston
seizure. Hopefully the damage is isolated
to the piston/rings/cylinder. The lower
rod bearing could be an issue but
will be easier to fix if it is just the
top end. You will have to pull
the head/cylinder off to check for
damage. Check the rod up and down for
any excess play.

An engine compression test might tell
you something but a leak down test
is better. It checks for leaks
by putting pressure in the spark plug hole
and listening for leaking air.

It might be just as quick to pull
the top end and check things out.

You may want to pull the side covers
first and make sure your flywheel rotor
has not come loose but it sounds like
a partial piston seizure to me.

Good luck!
Wayne S.
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