yamaha pro v 150 overheating at idle

crat13

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Hi guys, I,ve read several of your threads and it looks like you guys have plenty of collective knowledge to help me out. I have a 1990 150 pro v that runs like a top. Problem is there is an overheating alarm that goes off if the motor is ran under about 1000 rpm for about 6-8 min. Understand that it runs great with no overheating as long as the rpm is kept from 1000-5500. I have replaced the wpump and after heating the tstats up in the wifes tea pot (she really loved that idea) they open up at about 110F so i think they are good. There wasn't any corosion around the wpump or any that i can see from the tstat housing so i think im good there. The water peeing out isn't what i would call too hot when the alam sounds. Could i have a bad temp sensor? How can i check? By the way, this engine has never seen salt water, probable explains the lack of corossion. Any ideas will be great.
 

99yam40

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Re: yamaha pro v 150 overheating at idle

Like the top thread says it is best to give your model # so people know what motor you are talking about.

I believe that if the PRV is stuck open or partially open it will dump cooling water before it flows through the motor and not allow the water to fill the block completely causing the top cylinders to over heat at idle .Once you bring up the RPMs enough water will flow to do its job.
 

crat13

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Re: yamaha pro v 150 overheating at idle

sorry about that i'm new to this so bear with me. it's a pro v 150f. Not sure what a prv is???pressure relief valve? Where is it located?
 

crat13

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Re: yamaha pro v 150 overheating at idle

It is definately a 150F but I'm not positive that it's a 90 model, maybe an 89. Are these 2 the same. I really appreciate your help.
 

99yam40

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Re: yamaha pro v 150 overheating at idle

Maybe a 91. look it up at the part web site and see
 

crat13

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Re: yamaha pro v 150 overheating at idle

Looks like all the 150's around that year use all of the same prv s. I've got 1 coming and I'm confident that this will do the trick. Thanks for your time and patience. If your ever in Northeast LA I owe you a cold one.
 

99yam40

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Re: yamaha pro v 150 overheating at idle

Have you pulled yours to see if it has a problem yet?
you need to, just to see what is wrong and what all parts are needed. Gaskets, spring, grommet, lots of corrosion,etc.
Hey, I can always use a extra cold one. But do not run through there very often
 

crat13

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Re: yamaha pro v 150 overheating at idle

Not yet. Been working. Should be able to take it down this weekend. Of course I didn't think about what all was in there before I ordered the pov. But at least I did get a gasket. Maybe I'll luck out.
 
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