I have a Husky with a 21HP B&S. Some time back I fitted a dual temperature display to monitor the Transaxle temp (usually 65DegC) and the engine (oil filter) temp (usually 70DegC) and I have kept an eye on them both over the last few years. Tranny Temp is still the same but more recently I have noticed that when I finish mowing (the usual lawns) the engine temp is 99 to 105DegC.(221DegF).
Is that too hot? and any ideas what could be causing this heat creep?
I would suggest that the transmission oil temperature is low and the engine is now about right.
In general - oils are engineered to be most efficient in the 95 -110 C continuous range and suffer no ill effects if they peak, for a short time, up to 130C.
The rise in engine oil temperature could be related to oil formulation change, dust/debris on the cooling fins, higher load (mowing faster/blunt blades, your weight, etc)
If in doubt, contact the oil manufactures technical advisory service for a more informed comment.
