Thermostat removal on 84 Johnson 115?

[parrisw]

I want to change the t-stats on my 1984 Johnson 115, any tips to doing it? Does the powerhead need to be removed? I can't see how to get at the lower bolts, I can get on the upper bolt, but I can't even get it to budge, I think she is siezed in there good!!! What should I do.

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

Ok, I pulled the lower plastic cover off the rear, I can get a wrench on the bolts now, but boy are they tight, don't want to break them off.

 

[bktheking]

Re: Thermostat removal on 84 Johnson 115?

Looking at the back of the motor, follow the two black coolant hoses to the exhaust housing adapter at the bottom of the powerhead, they are attached to the stat housing. There are o-rings, relief valves and relief springs as well as your thermostats (2) plus 2 gaskets. Do it all, the valves and springs are cheap (compared to the stats) Check the hoses too at the same time.

You should NOT need to pull the powerhead.

 

[bktheking]

Re: Thermostat removal on 84 Johnson 115?

Soak them with penetrant, you DO NOT want to break those off.

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

Looking at the back of the motor, follow the two black coolant hoses to the exhaust housing adapter at the bottom of the powerhead, they are attached to the stat housing. There are o-rings, relief valves and relief springs as well as your thermostats (2) plus 2 gaskets. Do it all, the valves and springs are cheap (compared to the stats) Check the hoses too at the same time.

You should NOT need to pull the powerhead.

Thanks. Yes I know where they are. I'm just having trouble getting it off. The bolts don't allow easy access.

Soak them with penetrant, you DO NOT want to break those off.

Yes been doing that.

Making progress, got the left bolt out as far as it will unscrew, got the middle one moving, I ended up making a custom socket on my lathe, I shortened a 11mm socket so as it would get on the bolt better, the right bolt I'm going to have a big problem I think the head is rusted smaller then orignal size?? 10mm or 3/8 wont fit. What to do? Man I just love these things!!!

 

[ezeke]

Re: Thermostat removal on 84 Johnson 115?

Cut the cowl and go straight in then fill the cut with epoxy. You can see where I did it on my older 115 in the attached thumbnail. I must have done that twenty times or more on that and other crossflow motors.

Giving them a good tap or two will help.

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

Cut the cowl and go straight in then fill the cut with epoxy. You can see where I did it on my older 115 in the attached thumbnail. I must have done that twenty times or more on that and other crossflow motors.

Heating the bolts and giving them a good tap or two will help.

Thanks, I was actually thinking of doing that!! I should of.

Ok, I got it all apart, what a *****!!!!! Though in doing so, I cracked the middle housing on the very outside corner, I think it'll be fine though, since its on the outside of the outer bolt, not where the t-stats go. Melted one of those little white valves too. Cant see how these t-stat's were working looking like they do. Now to wait for parts.

 

[Solittle]

Re: Thermostat removal on 84 Johnson 115?

Ok, I pulled the lower plastic cover off the rear, I can get a wrench on the bolts now, but boy are they tight, don't want to break them off.

I have a pair of 87s. Loosen the bots that hold the pan to the block. You may not need to remove the bolts just loosen then. That will give you a bit more clearence. Go for the bottom two bolts from underneath with 7/16" box wrench. You might soak all there bolts with PB Blaster or other penatrating oil. You can get to the top bolt with a 1/4" drive socket with a universal at the end of a long extension.

Assembly can also be a bit of a bear. The tip here is to put a very, very light coat of gasket sealer on the mating surfaces of all the parts while on your workbench. Wrap them all tightly with a couple of tie wraps and let sit overnight (I hold lightly in my vise). The gasket sealer will hold the parts together. It helps to have a friend help mount the assembly back in it's place due to the springs, bolts, etc. One guy works from above and the other below to insert the t-stats, housing & control valves with their springs. When you get all three bolts well started then snip the tie wraps.

Whilel some guys will drill holes in the pan to avoid the frustration of the above as mentioned in an earlier post - I would not do that because unless well sealed you get a lot of spray up on that pan when underway at speed. And I want as little of that water floating around my running engine as possible. I definately would not do that with SeaDrives which I have.

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

I have a pair of 87s. Loosen the bots that hold the pan to the block. You may not need to remove the bolts just loosen then. That will give you a bit more clearence. Go for the bottom two bolts from underneath with 7/16" box wrench. You might soak all there bolts with PB Blaster or other penatrating oil. You can get to the top bolt with a 1/4" drive socket with a universal at the end of a long extension.

Assembly can also be a bit of a bear. The tip here is to put a very, very light coat of gasket sealer on the mating surfaces of all the parts while on your workbench. Wrap them all tightly with a couple of tie wraps and let sit overnight (I hold lightly in my vise). The gasket sealer will hold the parts together. It helps to have a friend help mount the assembly back in it's place due to the springs, bolts, etc. One guy works from above and the other below to insert the t-stats, housing & control valves with their springs. When you get all three bolts well started then snip the tie wraps.

Whilel some guys will drill holes in the pan to avoid the frustration of the above as mentioned in an earlier post - I would not do that because unless well sealed you get a lot of spray up on that pan when underway at speed. And I want as little of that water floating around my running engine as possible. I definately would not do that with SeaDrives which I have.

Thanks for all the helpful tips!!

Will

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

Ok another question here. I got my t-stat kit. And the new kit the springs in it which hold the relief valves are way stiffer then the ones that came out??? Is this ok? Also which side does the round t-stat gasket go on? In my manual it shows different then how it came apart? Anybody got a good diagram?

 

[kenmyfam]

Re: Thermostat removal on 84 Johnson 115?

Ok another question here. I got my t-stat kit. And the new kit the springs in it which hold the relief valves are way stiffer then the ones that came out??? Is this ok? Also which side does the round t-stat gasket go on? In my manual it shows different then how it came apart? Anybody got a good diagram?

If you have the correct kit then the springs should be O.K.
What kind of manual do you have ?? some are not trustworthy.

 

[kenmyfam]

Re: Thermostat removal on 84 Johnson 115?

Check the diagrams here. Plug in your make, year and model and see if it helps with your dilemma.

http://shop2.evinrude.com/ext/index.aspx?s1=bf6ad09c53cead335fcfd8a6471c0f7f

 

[ezeke]

Re: Thermostat removal on 84 Johnson 115?

.....or, click the thumbnails.

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

If you have the correct kit then the springs should be O.K.
What kind of manual do you have ?? some are not trustworthy.

Its a factory manual, but for a 1980, the motor I have now is a 1984.

Thanks guys!!

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

Ok, finally got this thing back together last night!!!!!!!! GRRRRRR what a pain in the BUTT, with those new stiffer springs, man what a pain to hold it all in there and start the bolts. Finally done, now I can go on to the fuel system now, and get that sorted.

 

[kenmyfam]

Re: Thermostat removal on 84 Johnson 115?

Ok, finally got this thing back together last night!!!!!!!! GRRRRRR what a pain in the BUTT, with those new stiffer springs, man what a pain to hold it all in there and start the bolts. Finally done, now I can go on to the fuel system now, and get that sorted.

So far so good then. Keep us all posted as you progress.

 

[parrisw]

Re: Thermostat removal on 84 Johnson 115?

So far so good then. Keep us all posted as you progress.

Yes thanks! I got another thread going called overfueling, its covering my fuel system troubles. Getting that sorted too, doing a fuel pump swap.