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New to me motor that sat a year before I installed it. Has good compression, runs great in a barrel but it seemed like it was running hot so I gave it an extensive vinegar treatment to try to remove excess salt buildup. New waterpump installed.
Ran the boat in the bay and my suspicion was confirmed, tach gave the overheat horn after 15 minutes at 4000 rpm. Did some research and after checking thermostats and poppet valve I pulled the head covers and heads.
Extensive salt/calcium buildup around the cylinders, passages and inside head covers. Cleaned everything up, confirmed no blockage by dropping lower unit and running hose up the water tube the water pump meets. Water flow is great, water pours nicely out of top of heads with thermostat covers removed.
Run the boat over an hour at varying cruise rpm's with no overheat. Problem solved, but...
I have always heard you should be able to rest your hand on the head of a two stroke without it feeling scalding hot. I've owned 4 other 2 stroke yammies and don't remember any of them feeling this warm.
Starboard side seems normal, can rest your hand on it comfortably for several seconds. Port side, scalding hot. No more than a second or two.
So, no alarm, but the engine FEELS warm. Am I overthinking this or is there something else I should look at?
I've ordered new thermostats just to be sure and pulled the inner and outer exhaust cover just to verify no blockage, was some salt build up and carbon buildup but nothing major. waiting on new gaskets.
Sorry for the novel, anyone have any insight as to how hot this engine should feel?
Ran the boat in the bay and my suspicion was confirmed, tach gave the overheat horn after 15 minutes at 4000 rpm. Did some research and after checking thermostats and poppet valve I pulled the head covers and heads.
Extensive salt/calcium buildup around the cylinders, passages and inside head covers. Cleaned everything up, confirmed no blockage by dropping lower unit and running hose up the water tube the water pump meets. Water flow is great, water pours nicely out of top of heads with thermostat covers removed.
Run the boat over an hour at varying cruise rpm's with no overheat. Problem solved, but...
I have always heard you should be able to rest your hand on the head of a two stroke without it feeling scalding hot. I've owned 4 other 2 stroke yammies and don't remember any of them feeling this warm.
Starboard side seems normal, can rest your hand on it comfortably for several seconds. Port side, scalding hot. No more than a second or two.
So, no alarm, but the engine FEELS warm. Am I overthinking this or is there something else I should look at?
I've ordered new thermostats just to be sure and pulled the inner and outer exhaust cover just to verify no blockage, was some salt build up and carbon buildup but nothing major. waiting on new gaskets.
Sorry for the novel, anyone have any insight as to how hot this engine should feel?
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