Opinions needed - Risk of Changing Thermostat

[FishAtFive]

I have a 1987 50hp Evinrude. E50TLCUD.

At operating temperature the head reads about 140 degrees max. The pee flow is pretty much constant, doesn't change, cold, warm, hot, doesn't matter. This motor has a history of brackish water, and getting the lower unit bolts off, I snapped three of the four.

I am debating if it's worth the risk of changing out the thermostat and possibly snapping a bunch of bolts, or it's better off just to run with a potentially stuck thermostat.

Thanks, I appreciate your wisdom on this.

 

[Crosbyman]

personnal decision... but if the thermostat is 38 years old you could always risk it.
heating surfaces around bolts with several and the patient application of a release agent will sometimes make it easy or almost. Let the capilary work do its work patience brings joy. sometimes a short clockwise jolt from a small 1/4 inch impact driver can break the bond then go CCW.

I have used and found Dupont brand snowblower silicone spray to be very effective with it's high capilary coefficient .

 

[racerone]

Water from the telltale does NOT circulate through the block.

 

[saltchuckmatt]

Probably would have ran some chemicals through it but since you snapped the bolts you have your work cut out for you. I'm also in bracket water and I always heat the crap out of them...and when I say "Hot" I mean hot.

Then I use children's crayons on them.

Best way to get yours off is to weld a stainless steel not on it...I do it with a small 120 stick welder.

 

[FishAtFive]

Probably would have ran some chemicals through it but since you snapped the bolts you have your work cut out for you. I'm also in bracket water and I always heat the crap out of them...and when I say "Hot" I mean hot.

Then I use children's crayons on them.

Best way to get yours off is to weld a stainless steel not on it...I do it with a small 120 stick welder.

No I haven't started the job yet, just debating if I should. 14 bolts!

 

[racerone]

Post pictures of cylinder head cover.

 

[saltchuckmatt]

No I haven't started the job yet, just debating if I should. 14 bolts!

There's more bolts than 4 on the gear case, look for the hidden one.

I would not run it with 3 broken bolts on the gear case.

 

[FishAtFive]

There's more bolts than 4 on the gear case, look for the hidden one.

I would not run it with 3 broken bolts on the gear case.

No I'm talking about the cylinder head cover I need to remove to get to the thermostat. 14 bolts. The three bolts I broke getting off the lower unit I got out fairly easy with vice grips.

 

[saltchuckmatt]

No I'm talking about the cylinder head cover I need to remove to get to the thermostat. 14 bolts. The three bolts I broke getting off the lower unit I got out fairly easy with vice grips.

I understand, but there should be at least 5 bolts to get the LU off.