Changing Thermostat on 85 15hp

[timsmcm]

I have a 1985 e15rcob 15hp. The motor runs good and works great. I have started to do some maintenance that the motor needed and I am trying to change the thermostat on the little motor. I cannot get the head plate off to save my life. Do I need to lift the powerhead off to get this off? The head of the cowl latch screw is in the way and there is not enough room to get that out of the way. I have a 81 service manual but it does not say weather you need to pull the power head or not. Please I need help guys I have this thing apart and know it needs a new thermostat lots of gunk down there around it.

 

[timsmcm]

Re: Changing Thermostat on 85 15hp

bump

 

[lbentz]

Re: Changing Thermostat on 85 15hp

yea, I have one of those here right now, but mine is a year older. It's actually easier to pull the head, because like you say, the latch is just tight enough to get in the way. Tearing it apart was fun enough, but when you put the thermostat spring and housing back on, it will be next to impossible.

I just had my 1984 Johnson given to me, by a past customer and all I found wrong with it, was a seized thermostat. I'm going to pull the head and make sure that the water jackets are all clean and recoat the inside with fresh new primer, so it'll be protected from future corrosion.

Good Luck. I hope this helps.

 

[BaitThrower]

Re: Changing Thermostat on 85 15hp

Just done this recently on my '86 15hp.

Basically you can't get the water jacket plate which holds the thermostat off without a lot of trouble, so you have to take off the cylinder head cover and then the cylinder head water cover off after that to access the thermostat. Quite a right royal pain in the bum actually. On 87 and older models they actually moved the thermostat to the top part of the motor to make life easier. That doesnt help us of course.

You might want to buy a new water jacket gasket and cylinder head gasket too while you are at it and put the new ones in while you have the head off.

The trick is getting the lower head bolts back in tight enough on re-assembly. I had to use a cut down hex-shaft socket turned by a 1/4" spanner on the socket shaft to tighten the lower head bolts. Not ideal but it works.

I made sure I cleaned out all the water jacket passage ways while at it. I didn't prime them while off though but I cleaned them up with sandpaper and they were just about new. Maybe prime next time...

Good luck!

 

[timsmcm]

Re: Changing Thermostat on 85 15hp

Thanks gentlemen I was thinking that that was going to be the jest of it. I read on some page that has a lot of info on the 9.9/ 15hp that you could do it with out pulling the power head and or the head off, just the head cover. It said something like you need to pull the cowl latch bolt out before you do it, and I said to myself after looking at the thing for a little while, man that man must be talking about a different motor than the one that I have because it is not coming out with no more than a 1/4 inch between the cowl latch bolt and the head cover. say la vie sorry if it is spelled wrong.

 

[timsmcm]

Re: Changing Thermostat on 85 15hp

Ibentz what are you talking about primer on the inside to stop corrosion. What type of product are you talking about because it is very hard to get anything to stick to aluminum when you paint?

 

[Vlantir]

Re: Changing Thermostat on 85 15hp

Hi I am trying replacing the thermostat on my 15 ph Model be 15baenm Serial no B08916066.I see you say after 1986 the thermostat moved to the top.My motor codes indicates year 1992 but sits on the bottom strange any explination for this. The cover plate has nine holes.

I can loosen all the bolt`s on the thermostat housing and can see the thermostat but cannot come far enough back as the thermostat spring is now getting in the way to remove the plate.

I can`t remove the moto cover clip bolt I can only loosen it, as it hits against the thermostat cover plate.It seem Please help what can I do as I have to replace the thermostat is there any other way of doing this.What is the correct part no for spring and thermostat.Please I need help as the bass are on the bit in Sunny South Africa.

 

[timsmcm]

Re: Changing Thermostat on 85 15hp

I would say that you need to pull the head and the head cover off together and do it like that. And also use some kind of omc gasket sealing compound on all of the bolts to keep them from comming out I torqued mine down like it said on the head cover bolts and they worked themselves out, the gasket sealing compound works like threadlock.

 

[Rick.]

Re: Changing Thermostat on 85 15hp

I just had the stat out on my 83, 9.9 and here is how I did it. I removed the cowl latch first. Then the water jacket plate from the head. The bottom bolt of the water jacket plate won't come out unless you remove it from the threads and then lift it out with the water jacket plate. Once it clears the back of the cowl you can then remove the bolt completely. I believe the 85 is the same. No one told me it couldn't be done so I just went ahead and did it. I know it was difficult to restart the threads of the cowl latch but not that hard. Rick.

 

[Vlantir]

Re: Changing Thermostat on 85 15hp

Could you please tell me how one can remove the cowling latch as the bolt hits up against the thermostat cover.Please help

 

[Rick.]

Re: Changing Thermostat on 85 15hp

As the bolt is loosened twist and pull outward on the latch. the latch should move out which will take the slack out as you go. If it wont move out spray it with some WD40 to free it up. Rick.