I just bought a used YS 61 and want to buy some replacemant parts for it. It seems it does not need them right now but I like to have them on hand. The side of the case reads YS 61 S. It seems to have low compresion but is turning a APC 11x 7 @ 14,100 on 15% power master. It has a mac quite pipe on it. I really had to lean out the bottom end on it, and it's still a little to rich at idle and mid range, I still have a bit more ajustment on the pump, but can only srcew it in maybe 3/4 of a turn more. Maybe it needs a rebuild on the pump. I own 3 ys 45 fs engines and a 120-fs so I have experiance with rebuilding the pump.

Please advise.

Regards, Dennis

If its a 61 then its the long stroke. It also has a square looking head on it. The YS 60 was the short stroke engine and is a round head.

Regulator is probably in need of a new diaphragm. They will deform and then you have to dial the regulator adjustment screw in really far to get it to work. This engine is well over 15years old and probably needs the new diaphragm.

Contact Richard at www.yspartsandservice.com for parts I'm sure he has some for the 60's and 61's

Troy Newman
Team YS Performance

Thanks for your help.

Regards, Dennis