90 hp yamaha

[1662]

i have a 2002 90hp yamaha, and after about 6-7 minutes of ideling or slow trolling the warning buzzer goes off. there is water comming out of the pee hole. you can shut it off for a while and recrank it, 2-3 minutes the buzzer comes back on. it does the same thing with the water hose hooked to it.

 

[99yam40]

Re: 90 hp yamaha

when was the last cooling system maintenance and what was done?

 

[hewes90hpyam]

Re: 90 hp yamaha

It could be a bad thermostat, the book gives you the readings that it should close and open - simple test, hot water and an ohm meter.
Is the water cool coming out the pee hole?

 

[99yam40]

Re: 90 hp yamaha

Hewes,
I am not sure what you would need an ohm meter for to check a thermostat, but you would need a thermometer to see what temperature it opened and closed at. you just look at it a see when it opens and closes. Maybe you were meaning the over temp switch

 

[1662]

Re: 90 hp yamaha

i am trying the boat out. i know the man, that i am getting it from, pretty well and dont think that it has ever had a new thermostate. i ordered a new thermostate today, thinking that it was pobably that or a sensor out of range. you know mechanics, were going to work on something some before we let anyone else touch it.

 

[99yam40]

Re: 90 hp yamaha

What about the water pump and the pressure relief valve? have they been replaced before?
I would be looking at them first and maybe pulling and testing the stat and temp switch as they can be tested to see if they have aproblem
Is this a salt water run motor?

 

[1662]

Re: 90 hp yamaha

the boat has never been in saltwater and would you still consider the pump with the water comming out of the pee hole. the pressure relief valve is a good thought and i never thought about that. really i didnt know that a outboard had a relief for the coolant system. are you thinking that the pump is worn and doesnt have enough flow? is the sensor a single post that changes ohms, as the temp increases? or is it a 2 wire that is simply on or off at the threashold temp. if it is the 2 wire it should be easy to dummy wire it, to shut the buzzer off, if i check the engine temp with a heat gun.

 

[99yam40]

Re: 90 hp yamaha

Yes it is a good idea to replace the water pump every few years, it is rubber and will get weak and R&R ing the bolts is good to keep them from binding up.
PRV can cause low RPM overheat if stuck open but run OK at higher RPMs.
I do not know if your motor has one, but I think it does

2 wire I believe and it takes it to ground to set alarm, you will have to check to make sure.

Manuals can be found and down loaded from the web if you look hard enough.
I prefer the Yamaha service manual as it is for you motor that you buy it for not a bunch of different ones like most of the aftermarket ones

Always best to test what you can to rule out all you can before replacing parts blindly

 

[1662]

Re: 90 hp yamaha

thanks for your help,time to do a little work.

 

[Geauxfish00]

Re: 90 hp yamaha

Hello, this is my first post. I too have a 90 hp yamaha from 2002. I've used it quite a bit in salt water and never had any maintenance done to the waterpump. I realize this is bad. I'm getting the audible alarm after idling for a while or with the hose hooked. The water is coming out of the tattletail but is very hot.

Does this sound like a thermostat issue or a waterpump issue? If it stops after I let the engine cool, what could be the risk with damaging something permanent?

I have a fishing trip planned for this weekend. It's only a 10 min run from the landing, but I don't want to do any permanent damage. I'm just trying to figure out if it's worth the risk. Thanks. Geauxfish00.

 

[Geauxfish00]

Re: 90 hp yamaha

i have a 2002 90hp yamaha, and after about 6-7 minutes of ideling or slow trolling the warning buzzer goes off. there is water comming out of the pee hole. you can shut it off for a while and recrank it, 2-3 minutes the buzzer comes back on. it does the same thing with the water hose hooked to it.

I'm curious to know how you resolved the issue?

 

[99yam40]

Re: 90 hp yamaha

Don't risk it.
It is hard to believe no maintenance has been done on this motor for that many years
fix it before you have to spend a lot of money on a screwed up motor.
heads, pistons, cylinders get expensive to fix

Just an opinion

 

[1662]

Re: 90 hp yamaha

i dropped the lower unit and put an new water pump impeller in. it doesnt look like it fits, but you bend the fins around, in the housing. i also took the thermostate housing off ( top back of the engine ) and cleaned the pressure regulator. i really think that the impeller was the fix. it just was not moving enough water. i have not had any more problems with heating. now having a problem putting it in reverse sometimes, i think that it is ideling too high.

 

[Geauxfish00]

Re: 90 hp yamaha

I picked up a new thermostat and gasket and a water pump impeller kit today. The thermostat will be my project this evening and the water pump over the weekend. Hopefully, the thermostat will get me by on this short fishing trip.

 

[83swampman]

Hi all, I have a 2007 Yamaha 90 hp I want to install on my 20' 1993 stardust pontoon. I currently have a Johnson 40 that is way too small.
I was think of adding a jack plate to give me some lift for shallow water cruising. Whats you thoughts on installing a jack plate or not?