I used my 1997 Craftsman tractor with 15.5hp Kohler engine all winter for plowing my steep driveway. The first time mowing I began to lose power and (even with the moer deck off) it now barely moves up any incline. The air and fuel filter are fine an the oil is freash and full...any thoughts?

ballengerb1

Do a compession check and come back here with your numbers. Could be a stuck valve or burned ring.

MOWERMAN2468

yes check the compression.

Tenaka

I believe the compression is fine. Further analysis shows that once the tractor has been running a while (less than half an hour) is when the power loss occurs. THe engine does not appear to be overheating and does not stall or idle badly....simply no drive power. The drive belt is in good shap and does not appear to be slipping.

ballengerb1

Humor us, this may end up as a process of elimination and a compression check is the most likely place to start.

Tenaka

I have checked the compression and it is 75psi, cold or hot engine (when power is lost).

ballengerb1

Does the ngine reach full RPMs when not under a strain? What happens to RPMs when you engage the blade?

Tenaka

Engine RPM does not drop, even with the blade engaged. The mowing blade has no effect on the problem, even if I let it heat up without the blade, it loses power. For information, is the 75psi a normal compression?

ballengerb1

So your engine continues at the normal full throttle RPM but you loose speed, this must be s belt slipping. Have you checked the drive belt tension and adjusted?

MOWERMAN2468

I am thinking that the belt is getting hot, and is either glazed, or is stretching.