'87 Yamaha 150 Running Hot at Idle

[THEFERMANATOR]

My question is always, have you verified that it is actually overheating? Thought those engines were pretty basic with not much of anything to worry about. One thing I would look at is if air is getting in the cooling system. I know failing head gaskets can push air in at slow speeds and cause overheating, but at higher rpm's the water flow is enough to overcome the air getting in.

[reelapeelin]

Originally Posted by THEFERMANATOR

My question is always, have you verified that it is actually overheating? Thought those engines were pretty basic with not much of anything to worry about. One thing I would look at is if air is getting in the cooling system. I know failing head gaskets can push air in at slow speeds and cause overheating, but at higher rpm's the water flow is enough to overcome the air getting in.

Ferm, when I shut it down and take the cover off, the top of the heads where the T stats are is VERY hot..leave the cover off for 15 or so minutes, try the ignition til the horn doesn't sound and she'll run great.