1990 Yamaha 200 hp waterflow/overheat problem

sofwarrior

Recruit
Joined
Apr 8, 2012
Messages
3
Can anyone give me advice on a waterflow/overheat problem with my 1990 Yamaha. The last time I used it there was no overheating issue. I start it up every couple months to get the gas flowing through the carbs and it starts fine. The problem is no waterflow and it overheats. Here is what I have done:
- I replaced the thermostats so that should not be an issue
- I pulled the poppet valve and both the valve and spring look good
- I started it up with both the poppet valve and thermostats out and covers off and there is no water flowing up this far.

I am thinking water pump but before I take the lower unit off I wanted to get some advice on if I am on the right track or are there other suggestions.

thanks for taking a look

Kevin
 

sofwarrior

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Joined
Apr 8, 2012
Messages
3
Re: 1990 Yamaha 200 hp waterflow/overheat problem

Anybody??? Someone has to have some suggestions or ideas???
 

erniefish

Petty Officer 2nd Class
Joined
Dec 11, 2007
Messages
153
Re: 1990 Yamaha 200 hp waterflow/overheat problem

i would say waterpump, you may also hook a old garden hose(end cut off) to the watetube extending down the center section, check flow, that will eliminate any other variables
 

sofwarrior

Recruit
Joined
Apr 8, 2012
Messages
3
Re: 1990 Yamaha 200 hp waterflow/overheat problem

Thanks Ernie. I did as you suggested and have good flow up through the thermostats. I pulled the water pump off and the impeller looks good but I guess I will do a full water pump replacement and hope that does it. I will let ya know.
 

jb200025

Recruit
Joined
Jan 25, 2011
Messages
3
Re: 1990 Yamaha 200 hp waterflow/overheat problem

With lower unit and thermostat housings off, push water through the thermostsat canal to backflush anything that may be in the engine.. it can only help and will dump water out the tube below. I also connected the garden hose ears to the lower unit and ran water with the water pump off to clear anything in that area as well.
 
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