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i found the problem on my 86 yz80 now i need help fixing it

Posted: Sun Oct 23, 2005 4:20 pm
by Todd
well i had posted a topic before trying to figure out how to fix my problem on my yz80 well i turns out that the engine had been running to lean and the piston is gone along with the ring so i was wondering how to get the piston out...how do i get that pin out? do i need a special tool or something? ;

Posted: Sun Oct 23, 2005 4:34 pm
by BuzZz
You have to unbolt and remove the cylinder, this will expose the piston pin so you can remove it and change the piston and rings. Check the bore for score/scuff marks and get it bored out if needed. Don't buy the piston untill you know if you need an oversize unit to fill up that overbore.

Posted: Sun Oct 23, 2005 4:45 pm
by Todd
but the pin wont come ouot do i just put a push pin on it with a hammer and knock it out?

Posted: Sun Oct 23, 2005 4:47 pm
by BuzZz
Did you take the circlips out? It may require a slight bit of persuading with a blunt object, but be careful not to bugger the con-rod. Try rocking the piston as you push on the pin.

Posted: Sun Oct 23, 2005 4:48 pm
by Todd
where are the circlips?

Posted: Sun Oct 23, 2005 5:40 pm
by BuzZz
They would be the little pieces of spring wire holding the pin into the piston. They fit into grooves cut into the piston pin bosses of the piston, one at each end of the pin. If you can see the ends of the pin, the circlips should be plainly visible holding the pin centered in the piston.

Posted: Sun Oct 23, 2005 6:54 pm
by nitrus
you might stuff some paper towels around the crankcase to keep the circlip from dopping down in there.

Posted: Sun Oct 23, 2005 7:12 pm
by BuzZz
Good idea. Sounds like there may be lots of small parts flying around. :wink:
:laughing:

Posted: Mon Oct 24, 2005 5:06 am
by Todd
thanks for the help guys it worked