maybe i need to check it with a tach?

[jerry-ahrens]

Not necessarily. Vacuume leaks can often occur without fuel leaking externally. I’ve seen it many times.

[gjonz]

As a follow up…my Lyman and 1957 Johnson 35hp ran 110 miles round trip Sunday with a 12 pitch…two adults…and three 6 gallon gas tanks. Average 23mph. Topped out around 27 or 28mph due to hull design.

Had a great trip. But I’d still like to go to an 11 or 11 1/2 pitch if I could find one.

Greg

[outbdnut2]

Propco propellers has an 11-1/2 pitch prop for $84.00. Go to the link below and click on Johnson and Evinrude at the upper left when it opens.
Dave

http://propcopropellers.com/

[gjonz]

Thanks!

Greg

[vintin]

quote gjonz:

As a follow up…my Lyman and 1957 Johnson 35hp ran 110 miles round trip Sunday with a 12 pitch…two adults…and three 6 gallon gas tanks. Average 23mph. Topped out around 27 or 28mph due to hull design.

Had a great trip. But I’d still like to go to an 11 or 11 1/2 pitch if I could find one.

Greg

That sounds like pretty good performance for that motor and load.

Any idea what rpm @ top speed?

[gjonz]

I think it was sitting right at 4500. Going by ear.

I’d like to try a 11 1/2 pitch or 11 just so I can see if I can run the motor less hard. But speed is typically dictated by hull design. To overcome that you must use brute-force. But I’m curious about a little less pitch on this boat.

Greg

[vintin]

quote gjonz:

I think it was sitting right at 4500. Going by ear.

I’d like to try a 11 1/2 pitch or 11 just so I can see if I can run the motor less hard. But speed is typically dictated by hull design. To overcome that you must use brute-force. But I’m curious about a little less pitch on this boat.

Greg

Here’s some information I gathered on six props I was comparing. All runs were made six times. The tach used was the type that wraps around a spark plug wire and seems to be very consistent. Speed is by GPS. I really couldn’t tell much difference in rpm by ear. I’m not sure who made some of the props but all were in good shape. The boat is a 1958 Feather Craft Vagabond and my motor is a 1957 35 hp Johnson.

8-26-2016 propeller testing.

10 x 14 2 blade brass prop. 4830rpm speed 29mph AJC prop
10.375 x 13.25 file sharpened 4680rpm 29 and 30 saw 31mph twice PropCo prop G-11

10.5 x 13 4500rpm speed 28mph
10.375 x 14 4500rpm speed 28mph
Unkown prop 4740 rpm speed 28+mph
Real Carol prop 5100rpm 28mph. must be about 12 inch pitch.

[gjonz]

Thanks for the info.

I had a 2 blade 15 pitch bronze…but it was a turd on every boat/motor combo I tried. Lol.

Greg

[vintin]

quote gjonz:

Thanks for the info.

I had a 2 blade 15 pitch bronze…but it was a turd on every boat/motor combo I tried. Lol.

Greg

I’ve got that prop too and also a 16 and 17 inch.

I recognize your user name as a fan of AlumaCraft.

I’ve got several myself and think they are great ships.

Among mine are a 1956 Merry 14 and a 1956 Cruiseabout.

Good to see you on the forum!

Dan n.

[gjonz]

Nope…like Alumacrafts…but sold mine a while back.

I have a 1947 Penn Han Cartop (for sale-restored)…a 12 Starcraft…and a 15ft Lyman.

Been thinking of selling everything in my collection but the Lyman. Then maybe starting over at some point. Lol.

Greg

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