Yanaha 200 overheat low rpm

[everett clark]

I have a 1988 Yamaha 200 that I have a overheating problem at idle of about 5 to 10 minute time If I troll below 800 rpm.alarm sounds, raising RPM will drop temp below alarm. I have replaced the Thermostats and water pump impller.If I remove the strainers and put on monkey-ears during flushing it will not over heat. It runs fine at any RPM above 800-900. pee stream is strong at idle rpm. Everything looked good when water pump was rebuilt exsiting impller was in good shape, telling that that was not the problem. nothing seems to be stopped up in flow path. Engine has 45 hours run time on rebuilt power head. need some help!!!!

 

[Solittle]

Re: Yanaha 200 overheat low rpm

What you describe is a problem that will be solved with a new impeller. Your post is confusing as you say you repalced the water pump impeller and later say that the impeller looked OK when the water pump was rebuilt. I can't imagine anyone rebuilding a water pump without replacing the impeller whether it looks good or not.

 

[Mod2]

Re: Yanaha 200 overheat low rpm

Moving to Suzuki/Yamaha forum.

 

[rodbolt]

Re: Yanaha 200 overheat low rpm

try replacing the pressure relief valve grommet. most yamaha low speed heating can be traced back to this little rubber grommet<br /> good luck and have fun

 

[everett clark]

Re: Yanaha 200 overheat low rpm

I had a question as to why I did not replace Impeller when removing water pump, I did replace with a complete kit wear plate, cup housing. impeller and new gaskets. This did not solve problem. Thanks for reply.

 

[everett clark]

Re: Yanaha 200 overheat low rpm

Wayne. thanks for your reply. I have replaced the gromet and valve. however when I went to test run, engine will not start, checked fuel flow am not sure about spark. I was wondering if the thermoswitch may be causing the problem. The last time I ran the engine the buzzer went off and I might have let it run to long before I shut it down . It might be possible after shut down the temp continued to rise and triped the thermoswitch. Any ideas??????