Evinrude model U

[george-emmanuel]

Tom gave some great knowledge! The compression fittings are about .050 undersize. If you use modern versions they will jump thread as you tighten. I made all new ones on the lathe for a ’28 H Fastiwn I built.

The U in my opinion is a lazy starter. By that I mean it seems to start really rich and finally clears out. I’ve always felt the venturi is too big. One day I hope to try a Speedifour carb.

Tom is right on about those cotter pins in the wrist pins. Don’t use a slightly undersize cotter pin because it’s easy to install! Use a full size. I found that some have alignment issues with the holes on the piston’s wrist pin boss and the wrist pin holes. I did one and used an aircraft drill (needed for the length). I lined up the top piston hole with the wrist pin holes and ran the drill through to bring the bottom piston hole into alignment. I have seen 29 U’s using wrist pin clips!

[2fast4me]

Oooookay I cleaned the model “U” and preformed an autopsy to find out why it died 50 years ago, well it may have died long before that but the guy i bought it from had it since 1970. I’m amazed people keep things as long as they do, kindred spirits I think.
Well it is stuck and the pistons are near the top and the ports are open to the crankcase so i have Some debris in the crankcase and the rings show rust. I think it best to fill the crankcase with penetrating oil and let it sit, maybe even some 16/1 mix, any thoughts? Some people swear by acetone and ATF some swear at it.
I cleaned the carb, air horn and manifold and found one mixture screw missing and the top of the float Bowel slightly cracked at a screw hole. I have a plan for that.
Gas tank has two small holes. Not worried yet!
I pulled the flywheel and cleaned everything, no parts missing. I did some polishing also.
Getting it unstuck is a priority if it won’t i may just cosmetically restore. I’ve got pictures, but it’s late. Thanks for all the help!
Jim

2Fast4Me

[bobw]

If it’s showing rust, I’d fill it up with some Evaporust or Metal Rescue first to knock out the rust. Drain that off, then follow up with the penetrating oil. The 50/50 acetone/ATF does makes a good penetrating fluid.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[rapier]

Thanks for the input on this post. Will be a great help to me when I get to my 16hp and 20hp model Us.

[Author]

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