5 hp honda no cooling water circulating

[BorisMD3]

Hi all,

Just put the boat in the water, and while the engine started up great, it was soon very hot smelling. A quick check revealed that no water was coming out the water check hole.

I shut the engine down, put up the sails, and sailed around a bit with the cover off the engine to cool it off.

I then sailed over to the slip, dropped the sails, and started the now cool motor. It quickly heated up again -- same problem.

My motor is a Honda 5hp 4 stroke. Vintage ~1989.

Any ideas? It ran fine in the fall, so I doubt there is a plug in the intakes. I'm wondering about an impeller problem, but don't know how to check that. Also, the manual says "faulty thermostat", but I haven't a clue where that is on this engine.

Thanks for any advice.

Boris

 

[P 0 P E Y E]

Re: 5 hp honda no cooling water circulating

Hi Boris

I would suggest taking a look at the adult section of this fine forum.

A lot of things can cause an outboard engine to over heat.

I have seen salt build up in the thermostat housing, in the pump housing, junk stuck in the inlet,,,,and the worst being a bad power head mounting gasket where exhaust gas being blown into the cooling system.

One thing I try to stress to the sailing instructors that run our 10 safety boats: stop the engine and raise it up, look around to see if a large plastic bag or other object that was being held to the intake ports on the gear case is floating in the water in close proximity.

Not a good idea to remove the thermostat, check it for salt. If you have to, cut the inside part and remove it, Install the restrictor plate to regain the engineered flow

 

[BorisMD3]

Re: 5 hp honda no cooling water circulating

Turned out to be a bad impeller.

Stopped at the Honda dealer, picked up the impeller kit, and a repair manual and after an afternoon's work, she's running fine again.

Not a bad repair at all.

Regards,

Boris