Evinrude model U

[2fast4me]

Greetings members, Evinrude Model U, not much info out there on this one. I just picked up mine Sunday so I’ll be looking for advice.
It’s stuck so first order of business will be getting it turning again, it’s soaking in magic juice as i type. Missing some screws on the intake and carb and something loose with the flywheel, not sure yet other than that its complete. I checked in the Inner Sanctum and found an index for the motor but there does not appear to be an electronic copy of the magazine.
What do i have here?
Any info is appreciated, thanks.
Jim

2Fast4Me

• This topic was modified 4 years, 7 months ago by 2fast4me.

[wbeaton]

Sounds like you have a 1929 Evinrude Speeditwin. The carb is cast zinc and very fragile. Be extremely careful when you dismantle it.

Wayne
Upper Canada Chapter

uccaomci.com

[Randy in Tampa]

Early speeditwin , I have two one I believe to be 1930 but I was told it could be a 29 and also a 1931 electric start, hold onto it get running I’m sure if you need parts will be able to find them in this club we all would like to see the motor running and many of us are fond of square tanks, good luck and let us know when you get it unstuck 😉

Rotary valve Johnson’s Rule!

• This reply was modified 4 years, 7 months ago by Randy in Tampa.

[2fast4me]

Wayne and Randy, thanks I’m just in evaluation mode with this one and i may soak everything up with magic juice till winter. I don’t want to go backwards with it. I sure wish i could read the old outboarder article.
Jim

2Fast4Me

[wbeaton]

Was it this article from Jim Smith?

Wayne
Upper Canada Chapter

uccaomci.com

[Tom]

The U Speeditwin came out for the 1928 model year, and had an above water muffler. The ’29 had a number before the U, and had underwater exhaust. Which does yours have?

The ’28 U series had roller bearings on the main and crank pins, I think that was the first year for Evinrude to do that. Coils are shared with opposed twin Evinrudes of the same era. Some of the Fastwin 12 and 14 hp motors of ’28 and ’29 had aluminum hubbed flywheels, which didn’t hold up well. If yours has a steel hub riveted in, all the better. And like mentioned above, carbs and air horns are getting hard to find.

The cooling system works on a vented propeller. When spinning, the vacuum generated at the outlets of the prop pull cooling water up through the motor, then back down. For this to work, the water tube connections need to be airtight or nearly so. The original tubing and compression nuts were aluminum. Many have been replaced with copper. The compression nuts are NOT the same as those you can purchase today. So if there are copper lines or brass compression nuts on your motor, you’ll need to do some work. There are two V-shaped fittings on the back of the motor. One is supply, one is return. I’ve seen these set up backwards, so water enters the top of the cylinders and returns through the bottom fittings. Be sure yours isn’t set up this way. IIRC, the top V-fitting is the supply, the bottom is the return, but check that with some compressed air.

Be sure the cotter pins which retain the wrist pins are intact. Once unstuck, inspect the pistons carefully to assess their condition. Broken ring lands are not uncommon in my experience.

Good luck with the motor, these sound GREAT when they’re running!

T

[tinkerman]

Not trying to hijack the thread but this is good info for others as well. I also have a “u” model I will be starting on before long. 1928 or 29, can’t remember off top of my head.

It's a jungle out there.

[garry-in-michigan]

The ’29 racing model had dual carburetors. The last time I saw one raced was in 1950. It finished fourth in a field of twelve. Dad remarked that the connecting rods must really be getting tired by now. The first attempt at a “full jeweled” powerhead. A well set up model is not hard to pull over. You bounce it against compression to get a flying start on the pull.

• This reply was modified 4 years, 7 months ago by garry-in-michigan.

[2fast4me]

Tom,
1. Above water muffler.
2. No # before the “U”.
3. Steel hub on flywheel, steel hub riveted to aluminum flywheel.
4. Vented propeller-don’t know yet. Top of cylinders have copper fittings that do not connect to anything and no evidence of a 2nd “Y” pipe but i am still looking. I’ll try to get pictures later.
Thanks everyone!
Jim

2Fast4Me

[Tom]

OK, so it appears you have a ’28 Speeditwin. I believe that one has an impeller pump in the front of the lower unit, not a pressure / vac system and vented prop. The water just dumps out the top of the cylinders through short pipes.

Sorry for any confusion.

T

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