compression readings for 1957 Fastwin 18

[olcah]

I’m looking at a Fastwin 18 and the gentleman selling it reports compression readings of 118 and 120. I have also seen a reading for this motor of 150 – quite a bit higher. Which makes me wonder – what are reasonable readings for the motor using the manual rewind?

[Mumbles]

I’d be real happy with those 118-120 numbers but you might want to check them yourself. Electric start motors will usually give higher readings than can be achieved by roping it over manually.

[lloyd]

As usual, I agree with Mumbles. I have numerous OMC 18’s and 120 psi is just right for that motor. They will idle and run great with anything over 110-115 psi. Never seen or heard of one with 150 psi. Be sure to double check it yourself cold and dry with no added oil in the cylinders.

[Tom]

It was checked cold (60 degrees F) and dry, with no oil added to the cylinders or intake. Five pulls for each test. Gauge was a Craftsman 47089.

Tom (currently the caretaker of the motor)

[crosbyman]

so is it 118-120 or… 150 who took the presumed 150 reading and did you try another meter

in any event if all else is OK incl price.. buy it !

Joining AOMCI has priviledges 🙂

[olcah]

I just ran across a reference to 150 someplace. I expect to buy it. In spring of 1959 my Dad and I went to Boston, turned in our 1953 Johnson 10 HP, and brought home a brand new 1958 Johnson 18 HP (same basic motor as the 57 Evinrude). Right out of the crate and started in the test tank. We put it on the 12 ft. rear steer aluminum runabout, At wide open you had to watch what you were doing. Wonderful!

[lloyd]

Sounds good. I run my 18’s on an Alumacraft model R. With an AJC 417 2 blade speed prop it runs right about 30 MPH. Still my all around favorite boat/motor/prop combo.

[olcah]

Lloyd,
Are you running front or rear steering? Also is the Model R 12 ft. or 14 ft. long?

[lloyd]

Model R is 11 feet 6 inches and has a mid deck for steering so the driver sits on the rear seat and passenger sits on the front seat in front of the mid deck. Local friend of mine is selling his excellent Model R with Merc and trailer. I would buy his in a heartbeat but I already have 2 excellent Model R’s.

[outbdnut2]

Those 18s have good low end torque too! When I was 11 years old, back in 1958, my neighbor at the cabin had an 18 on a decked 14′ Alumacraft model F (rated for 16 HP max). Us kids skied double behind it, with one person in the boat up front driving.
Dave

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