1971 Evinrude Ski Twin 40 Restoration

[Midmainer11]

Good Morning,

I recently picked up a 1962 Mirrocraft with a 1971 Evinrude Ski Twin 40 on it.

The bad:
The engine does not run
it was sunk 3 years ago, drained and flushed with marvel mystery oil and stabil.

The good:
Plugs were not rusty
borescope looks good with no signs of rust
feels like it has good compression but will confirm with a compression test tomorrow
I got the boat an motor for 200$

I am looking for your input on what I should be checking. what gaskets need to be replaced. what pieces should be rebuilt.

 

[racerone]

If any water remained in the bearings there will be problems after you get it running.-------------Only way I would do a project like that is a complete tear down of the engine for inspection.-----------Results and opinions will vary.

 

[Midmainer11]

I am planning to do a complete tear down. I've done a few sled engines and a wheeler. Just no outboards. Is it a throw away if the crank bearings are bad or worth changing out?

 

[gm280]

I am planning to do a complete tear down. I've done a few sled engines and a wheeler. Just no outboards. Is it a throw away if the crank bearings are bad or worth changing out?

Good to know you do plan on a complete disassemble and rebuild. I actually did that same thing to a '76 Johnson 40 HP engine. And I mean total disassembled as well. If you care to take a look, click on the engine link below and see. Can't say for absolutely certain, but I suspect there are still parts available for that engine. I will say that the lower foot section gear bearings they used in 1976 were merely Timken bearings. So save some money and buy Timken replacements and not OMC or Johnson replacements. The only difference is the price. They both have the exact same Timken part number on them. JMHO

Post a picture or three of your engine for us to see what you are dealing with. And :welcome: to iboats.

 

[Midmainer11]

Thank you very much for the welcome. I'm using this as more of a leaning experience than anything. I've never dug into outboards. Just sleds wheelers and vehicles. It was cheap enough to be a learning experience. I will definitely check out your thread.

 

[F_R]

I am planning to do a complete tear down. I've done a few sled engines and a wheeler. Just no outboards. Is it a throw away if the crank bearings are bad or worth changing out?

Yes---unless you can find some good used parts. Post a want ad on the Antique Outboard Club's website www.aomci.org The ad is free

 

[Midmainer11]

So I dug deep into the motor yesterday. Everything was in great shape. No rust evident in the cylinders or crankcase. Carb was even spotless. Gearcase was in great shape and all the bearings are good.

The only thing that I found to be in rough shape was the starter. Rusty as hell on the inside. And doesn't appear to be repairable. I'm going to soak it in rustdisolf to see if it will clean it up any. Thankfully the starter is non essential to the motor running. I will be actively looking for another starter for convenience and correctness.

Also 2 of the mounting bolts for the bottom of the case are broken off so I'll have to address that as well.

I need new gaskets for the head. Any suggestions as to the best place to find a complete kit?

I've determined that I'm not going to get new rings or bearings as the engine appears to have very little use and there is still great cross-hatch on the cylinders and I'm on a college student budget.

Now it is time to reassemble and paint.

 

[Midmainer11]

No Title

 

[tomhath]

Gaskets and seals are readily available for that motor. The first place to look would be iBoats, but I don't think they carry parts for motors of that vintage. You shouldn't have any trouble finding them with a bit of online searching.

 

[Midmainer11]

So I found all the gaskets and I also found a starter on eBay. Should have the motor back together this weekend

 

[gm280]

I realize your engine is a 1971 model, but it is very similar to my '76 version. I totally disassembled my engine and rebuilt it with new parts where needed. But I changed the color scheme. Other then that and the cowling change, they look basically the same inside. Post how your effort to save the starter works out. :thumb:

 

[Midmainer11]

I thought about doing a rebuild but it was in too good of shape to go with new stuff. And I'm still in college so funds aren't unlimited. I picked up an original starter on eBay for 25$. My still try the evaporust and see how that works. It should be all together minus the starter this weekend. May just throw it in the water to see how she goes before I start restoring the boat

 

[Midmainer11]

Anyone know the torque specs for the head and the torque pattern

 

[F_R]

168-192 INCH POUNDS. Start with one of the center bolts and work your way outward in a circular pattern. Start at half torque, then repeat at full torque. Retorque again after test run and cool-down.

 

[Midmainer11]

Well I got it running for a few seconds. Think I flooded it. It's kinda hard to pull start it on the stand so. I plan to have the starter by next weekend so I should be able to diagnose the issue. But it ran. So that's promising