ok. So I bought a 2005 rancher that is blowing oil out the exhaust. The person I bought it from put in a new piston and rings. I figured it might of had a broke oil ring on the piston But after I broke the motor down all rings look good.
Piston looks good as far as I can tell.
So I figured it would maybe be a valve seal bad. So I took the springs off the valves to inspect the seal. Both seals look good/ not damaged.
Any one have a clue of what I might can inspect next??
thanks
Ron

 

I've got a Honda 350 top end in at the moment, had been worked on by a tractor repairer who had put new rings in and found the bike to still be burning oil. He took it apart again and fetched piston head and cylinder to us, found he had bought standard rings, but the piston & bore are 1mm oversize, did you check bore size and ring gap? Always measure piston size, bore size and ring gaps to ensure you are within tolerances, before assembling the top end, and fit new seals anyway, just in case.