DT50 bogs and stops and has to cool down before restarting.

[seanymph]

I have a Suzuki DT50 2 Stroke. I just picked it up. It idles low in the water and wont quite stay started unless I raise the idle lever but then you cant engage gear. I can get it going by moving it into gear fast and gunning it. once I get it going it runs well until about 10 mins or so when it starts bogging down and comming off plane and pushing water. Then it just stops and wont restart until it cools down. The engine is so hot it sizzles when I take the cover off and the hose to the water pump nozel melts rite off. once the overheat cools down you can start again and the same thing happens but of course it only takes a couple mins to heat up the second time. I have changed the lower unit oil and greased the prop shaft. I emptied all the old gas and filled it with premium gas and used fully synthetic oil in the mix. I changed the plugs (for some reason the ones in there were not the correct ones) and I added some Startron Enzyme fuel treatment and sea foam to the gas. I also bought a new battery and wanted to add that the water pump appears to be working well and luke warm water is coming out the pump hose the exhaust and the prop. It runs and idles fine out of water. Could it be a fuel pump problem. I have also been told it could be a problem with the stator. The fuel filter appears to be clean.

[boats.net]

Well it is definately overheating, you may have a bad thermostat. Check compression, when hot. Verify spark to all cylinders. Fuel pump could be vapor locking, due to excessive heat. Look for melted wires on engine, could be grounding out ignition wires.

[seanymph]

forgive me for sounding stupid. Where is there a thermostate on this motor. When does it open and close. My understanding is that the water pump continuously pumps fresh water through the motor. Could it be a water pump thats going bad? I am not so familier with boats so maybe the water coming out the stream is softer than it should be. If so it would make sense the top of the motor gets so hot. Would less water equal higher temps? This engine is a 1983 (i think) if that helps. I did verify spark to all cylinders.

[seanymph]

one more thing. I just realized that when I start the motor out of water with the muffs on it idles fine and when I put it into forward gear it didnt make any noise. The prop was spinning but no motor rev or anything. Me and a buddy noticed it seemed odd but thought nothing else other than maybe it works harder when pushing water. I was just watching you tube and they were reving loud and fast.

[pinecpt]

Change your waterpump impeller and clean the carbs.Take them apart and remove jets and spray carb cleaner through all the passages.

[boats.net]

Waterpump could be the issue, however usually they would have a very soft and sometimes sparatic stream.