1994 Yamaha SWS 250 Overheat at Idle

[dteufle]

Hello,<br /><br />For the past three seasons I've had a problem with the overheat sensor going off after extended periods of idle. Last season I had a mechanic exhaust every possible thing it could be, according to him, and he could find nothing. He did replace the impeller/water pump, but it was pretty new anyway. Ran fine all summer, then the last trip over to haul out it went off. <br /><br />A little history: Engine has not been run much in the past 6 years, only 3-4 times a season. Engine does not get flushed after use (only runs in salt). Engine has had 2 prop shaft replacements (very rocky area). <br /><br />Thanks in advance.

 

[John from Madison CT]

Re: 1994 Yamaha SWS 250 Overheat at Idle

Once again, probably the Poppit Valve.<br /><br />Do a search here, you will find lots of info..

 

[sweetp]

Re: 1994 Yamaha SWS 250 Overheat at Idle

I have the same problem with my 2001 225 OX66. Just replaced the impeller and thermostats and at 500 rpms on the way to the fuel dock in the no wake zone the alarm sounds. I was also told to replace the poppit valve that I just purchased. Is this a simple replacement? Thanks and I will let you know if the problem is solved. I have only 100 hours and I flush after each use.

 

[rodbolt]

Re: 1994 Yamaha SWS 250 Overheat at Idle

the valve never fails. its the grommet. the corrosion builds up and deformes the grommet causing the valve not to seat. remove it, clean the pocket thourouhly with a pick and install a new grommet and usually all your idle overheat problems will be solved. dont oush the grommet all the way in. if you do post before attempting to remove the exhaust cover.