Very low compression on 40 year old 2 cycle outboard.

billr

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Any time tomorrow (after 8 AM, of course) would be fine. As a bonus, I will show you the carcass of that keyboard and how poorly the membrane is "sealed".

I am not convinced the compression is even all that bad. This is a very small-displacement cylinder, I suspect the volume of the compression gauge and hose is significant in comparison to the combustion chamber "squeeze"; dropping compression pressure read.

I don't have any 2-stoke oil, so bring some if you have it.
 

NickD

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Good point on the air volume in the compression gauge and its hose reducing the reading, other question is spark and fuel, not sure how old this thing is, but in the last 20 or so years, EPA eliminated the needle valves and if the jets are brass will corrode.

Smallest engine we ever had was a 50 cc or 3 cubic inches on a moped, good thing it had pedals, but a lot more difficult to pedal than a regular bike. Had to clean that spark plug every five minute burning two cycle oil.
 

JackC

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Nick: Yes, no needle valve and the one brass jet was very plugged up took 2 days of carb cleaner and lots of air air to blow it out.

Bill: I will be up this afternoon around 2 to 2:30.
 

JackC

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grcauto: Good call. I put 99% Isopropyl Alcohol in the combustion chamber last night and started it this morning.

Bill: Since it is running, I will NOT be seeing you this afternoon. That Alcohol is the gal. you gave me. I will miss seeing you. Maybe I can break something else.:fixed:
 

NickD

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Not much more than a model airplane engine, have several around here someplace. Doesn't even have ignition, just a glow plug and only used for starting. Noising little suckers, but do have a mixture adjustment, don't get your finger stuck in the prop when adjusting it.
 

nickb2

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Need to put it head first into a large can or tank with solvent and allow a few days to loosen it's grip on the rings. You'll need to devise a way to support it head down. I would crank it at times if you can do it. If not let it set for several days. Have everything ready to assemble. Take it out and crank it several times and install new plug and just hit it with some ether and get it started. Don't even test for compression. Even if it's low it'll likely start and the rings will seat in short order and the crude should burn off as it warms up.
Just sayin, common thing we do up here, and believe, we do even worse when it hits way below celcius.
 

NickD

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Could you strap that motor to your belt some how to power you wearing water skies? Would be a cool video to watch on youtube.
 
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