how big of a job is it to replace the piston and rings in a 1986 yfm 225

 

come on guys i need some help here where are all the moter heads at

 

The worst part is getting the engine out of the quad.
I did the piston and rings on my old yfm 80 not long ago, what is wrong with your yfm?
I had to do the intake valve, cam chain, piston rings and have an oversize piston put in

 

it is smoking real bad , when the choke is on or when you ride it and give it gas it smokes when it is running without the choke on it dosent smoke

 

I would think that maybe you have more of a carb problem because of it only being under throttle or choke, but maybe it could be collapsed rings.

Start by pulling out the engine, and then pulling the cam cover off the top end to remove the cam gear. Then unbolt the head and pull it off, have your local dealer check the head out because if you need a valve replace(probably a good idea, intake valves get beat into the head a lot on older model YFMs) this is the time to do it. Pull the cylinder off from the engine block if it needs to be bored out take it with you to the dealer to have them do it at this time. There should be a couple of rings on the piston pin that you have to pull out to remove the pin and piston.

 

the vent pipe on top of the motor smokes too , do you think i should get a rebuild kit for the carb and install before i try to take the motor out . i took the carb off before and just cleaned all the old parts and put a new gasket on it , so what do you think does it still sound like the carb or something else . by the way you have been very helpful i appricate everything

 

Well did it start smoking after you messed with the carb.

 

it has smoked since i got it ,when i first got it running as soon as you gave it gas it would die out then i cleaned up the carb and i got alot more power but it smoked from the tailpipe and the vent still i changed the oil and oil filter and there was shavings around the filter and the filter house i cleaned all that up put a new oil filter on it and new oil and ran it for a full tank since then i have put some lucas oil conditioner in it and i run it about 20 or 30 minutes every few days

 

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If you had a lot of metal shavings, it might be wise to tear everything down and see where they came from before spending money on fixing the smoking problem