Here's one for all you spanner people. I have a Yamaha 9.9 elec start 4 stroke long shaft on my N20. I have it at my local Outboard mechanic at the moment because it runs very hot. Apparently they expect them to run at 60-70 degrees however mine is showing around 110 degrees. They use a fancy thermometer to measure the temp therefore I have to trust the information they give me. They have changed the impeller & thermostat plus everything else is in good condition. They have just removed the cylinder head and say that the galleries are clear and the head gasket was in good order. All was put back together and run for 2 hours however the temp has hardly come down from 110 degrees....has anyone had any similar experience with this kind of issue ??
The water gallerys in the head have to be blocked or the tube up from pump to cylinder isn't sealing properly and the water is coming back down the inside of the leg before it even goes round the engine.
That is all it can be - reduced flow around the cylinder and head - ifr the impeller and pump housing are good and the pump isn't leaking, if the stat is fully open at the right temperature and the flow through it is good then you need to look at restrictions in where the water is then supposed to go.
Outboard Running Very Hot - help !
Posted - 16 Mar 2016 : 12:56:41
