Powerhead compatible with 1979 lower evinrude

[harleyguy302]

Hello

This is my first post. I'm new to outboards so have lots to learn and lots of questions. I have a 79 100hp evinrude (100999S) with a cracked power head. Just found out last night when I pulled off the head. Bummer. Any way so I hit craigslist to see about finding a new motor. I found a 76 115 HP Johnson (115ETL76). My question is since these are both V4 will this power head bolt up to my lower unit from the evinrude? The evinrude is set up fro dual cable steering and I don't think the Johnson is so I'd like to keep the steering setup.

Thanks for any help you can provide.

 

[racerone]

Re: Powerhead compatible with 1979 lower evinrude

Sorry, you will have to keep looking.-----Mounting gasket is different between the 2 blocks.----There would also be issues with shift linkages.

 

[harleyguy302]

Re: Powerhead compatible with 1979 lower evinrude

Just my luck!! Any way another question....The current block the water jacket is cracked but the cylinder is ok. The motor was running until I discovered the cracks. Has anyone one tried to weld this before? I know some good welders that could probably do the job. Also there are rubber hoses in the cooling passages in the block, what are these for?

 

[racerone]

Re: Powerhead compatible with 1979 lower evinrude

These hoses guide water around the block for proper cooling.----Note ----water does not flow through these hoses.-------Need pictures of the crack to determine if it can be repaired.

 

[harleyguy302]

Re: Powerhead compatible with 1979 lower evinrude

Thats what I thought the hoses were for. I will get pictures tonight. Thanks.

 

[emdsapmgr]

Re: Powerhead compatible with 1979 lower evinrude

Powerheads from 77 and up will fit your midsection. All these engines have the dual thermostats and hence, the later baseplate configuration. (The 77 will require you to change/swap your intake manifold.) The 76 and earlier models have only one vernatherm/thermostat, and they are the older configuration which won't interchange. As long as your block crack does not affect the running surfaces of the cyl liners or crank bearings surfaces, you should be able to get it aluminum welded. Alum welding does not develop the heat that normal steel welding does, so heat deflection/distortion is not as much a problem. A picture would be helpful.

 

[dazk14]

Re: Powerhead compatible with 1979 lower evinrude

As emdsapmgr said above, a picture is needed.

Depending upon the location, a properly prepared surface can be $12 Grey Marine-tex'd and provide a lasting seal.

It is superior to JB Weld for cracked engine blocks.

 

[Faztbullet]

Re: Powerhead compatible with 1979 lower evinrude

Not unusual for them to freeze and crack under head on starboard bank...easy fix with welder..

 

[boobie]

Re: Powerhead compatible with 1979 lower evinrude

Fazt, how and why do they freeze ??

 

[harleyguy302]

Re: Powerhead compatible with 1979 lower evinrude



Here's some photos.

 

[emdsapmgr]

Re: Powerhead compatible with 1979 lower evinrude

I've seen this problem on a few of V4 blocks-which have similar damage-at the bottom of the block-all from freeze damage. While rare, it does happen. This is a little more severe. Could be a problem, unless the repair is done correctly. If the bent casting pc is not bent back into the original (factory new)orientation-prior to welding, the head gasket will not make proper surface contact and will leak water at that location when running.

 

[dazk14]

Re: Powerhead compatible with 1979 lower evinrude

I've seen this problem on a few of V4 blocks-which have similar damage-at the bottom of the block-all from freeze damage. While rare, it does happen. This is a little more severe. Could be a problem, unless the repair is done correctly. If the bent casting pc is not bent back into the original (factory new)orientation-prior to welding, the head gasket will not make proper surface contact and will leak water at that location when running.

+1 - This is not a job for Marine Tex.

 

[harleyguy302]

Re: Powerhead compatible with 1979 lower evinrude

How does this happen? Is something plugged somewhere? I did notice when I pull off the caps on the heads they were packed with mineral deposits. Never heard of this on a outboard motor. It had good compression and ran. I had it running Monday getting ready to put on the boat. I bought this motor for a project boat 2 years ago. Wife already wasn't happy about project now if this can't be welded she won't be happy with me looking for motors again.

 

[racerone]

Re: Powerhead compatible with 1979 lower evinrude

Need to look for blockage of wee drain holes.-----Myself I would repair this with " LUMIWELD " rod.-----Or pick another block off the shelf.

 

[Faztbullet]

Re: Powerhead compatible with 1979 lower evinrude

Fazt, how and why do they freeze ??

Debris blocks the weep/drain hole and it gets cold up this way :smow:

 

[boobie]

Re: Powerhead compatible with 1979 lower evinrude

Fazt, I came from northern WI and never seen this happen. O'well you learn something new every day.

 

[harleyguy302]

Re: Powerhead compatible with 1979 lower evinrude

I talked with the welder today and he said this should be no big deal, wasn't concerned at all. Should be hopefully next week. I'll post a update when its back together and running. One quick question since I'm typing. Should I be using any gasket sealer when I remount the power head to the exhaust tube or are the gaskets good enough? Or when and where to use gasket sealer??

 

[emdsapmgr]

Re: Powerhead compatible with 1979 lower evinrude

Lower unit water goes up through part of that gasket, as well as exiting oily, unburned exhaust . Use sealer. You can use the Bombardier sealer: 317201. Looks a lot like the caramel colored Permatex sealer in a can, usually available in most auto stores. Either will work.

 

[harleyguy302]

Re: Powerhead compatible with 1979 lower evinrude



Here is what it looks like after weld. After we did this we discovered the other cylinder bank had the same cracking just not near as bad. Probably would not have even noticed it if I had not pulled off the head. Glad I did. Would have been upset if I would to had to pull apart again for this reason. I hope to get some time this upcoming weekend to get it all put back together and test it out.

 

[emdsapmgr]

Re: Powerhead compatible with 1979 lower evinrude

A nice, neat weld job. You should still get many hours out if it ahead.