How manny and where is the t-stats??

[drewmitch44]

I have a 115 ELTJ (1986 115hp) yamaha. Im wanting to replace the thermostats and impeller. Its a v motor and it seems like one side of the motor gets warmer than the other. The right side from looking at the motor from the back gets pretty warm and the left side stays really cool. The warmer side dosen't get hot enough where i cant touch it right there where the spark plugs go in but i dont think thats normal and i want to check and replace the t-stat's. My manual is pretty crappy and it dosent even tell you if there is more than 1 t-stat or where they are. Does anyone know where the t-stats are on this motor. And ive changed impellers before and its been pretty simple. Is there anything that i need to look out for as im doing this one? More than the impeller im worried about the 2 different temps on eather side of the V-block. Is there anywhere becides t-stats and impeller i should look for when trying to correct this problem. The motor runs great i just want to keep it this way for a few years. Thanks in advance!

 

[BruceAML]

Re: How manny and where is the t-stats??

It has 2 thermostats total one at the top of each cylinder head.

 

[Asainz320]

Re: How manny and where is the t-stats??

Im having the same exact problem with my 150hp yamaha. The right side block standing behind the engine is getting warmer than the left side. What is this due to?

 

[rodbolt]

Re: How manny and where is the t-stats??

each head has a t-stat, you also need to carefully clean the pressure valve pocket and replace the grommet.
if it leaks the top stbd head tends to overheat at idle due to loss of water pressure.

 

[drewmitch44]

Re: How manny and where is the t-stats??

Ok i pulled out the t-stat on the side that getts hotter. It opens up at about 132 degrees or so. What temp should these guys open up at? I am thinking about switching them around and see if the other side gets hotter. I figure if the problem followes the t-stat around then that will diagnose the problem. Im not sure what temp they are supposed to open up though. Also should i replace the gasket there that is on that stat cover? Thanks.

 

[drewmitch44]

Re: How manny and where is the t-stats??

The t-stat says 50 degrees celcius so that i think is 122 degrees F. i think my math is correct. Does that sound right? is this the correct t-stat for this motor? Thanks again.

 

[drewmitch44]

Re: How manny and where is the t-stats??

I pulled the 2nd one and they both seem to open up at the same time the thing is the 1st one that i was not sure of is now working better. Is there a way to clean these things. I think that there was some corrosion that was keeping it from working properly. I got all the gunk off that i could with water and a toothbrush and now it seems to be working better in the pot that i have them in. Should i wd-40 bath them? Or what do you guys think? These gaskets are 30 bucks a piece i just called the yamaha dealer and they said it will take 3 weeks to get them. Seems like a pretty common part so i dont know why they dont stock them. I bet yamaha's for a whole lot of years use this same t-stat.

 

[drewmitch44]

Re: How manny and where is the t-stats??

well thats what i did was cleaned the corrosion off of them with wd-40 and some other cleaners and penetrating oils. They are opening at 125 now and i reinstalled them and i cannot tell a difference in the 2 sides of the motor. They are both nice and cool and thats a good thing. There was some nasty crap in the cooling channels. is there anything i can use to flush it out when im running on the muffs to break up the salt crust and other yellow stuff in there? I want to make sure that the cooling passage is open good. anyway i just wanted to share how i corrected the problem the t-stats were just cleaned out and now they are working propperly. See ya

 

[BruceAML]

Re: How manny and where is the t-stats??

The correct Yamaha part number for the thermostats is 6E5-12411-30-00. That is a change from the original thermostats. The part number for the two thermostat cover gaskets is 688-12414-A1-00 and the list price is $3.14

 

[lord121645]

Re: How manny and where is the t-stats??

It has 2 thermostats total one at the top of each cylinder head.

What do you have to do to remove the t-stats?

 

[drewmitch44]

Re: How manny and where is the t-stats??

Lord there is 4 bolts on the top of each head. There is a plate that has what looks like cooling fins kinda. When you remove the 4 bolts the part just comes off. Then the t-stat is right there and there is a rubber gromet that surrounds the t-stat. That rubber piece comes out with the t-stat. I had to replace the gaskets for the plates i took off. They were pretty beat up looking i reinstalled like it is and it does not lead but i ordered 2 gaskets for them from boats.net. Hope this helps..