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Engine basics => Engine set up tips => Topic started by: Steve Thornton on July 27, 2012, 09:29:20 AM
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Does anyone have experience with the old Johnson 35 S? I inherited one that looks like new & good compression, but I have never started it. Wondering what type fuel, glow plug, etc. How does it compare to Fox 35 and OS Max 35 S?
Thanks for any input!
Steve Thornton
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I ain't no 'spert, but those are older engines, and I would suggest somewhere in the vicinity of 25% castor, with 3-5% syn to help keep it "clean".
Also maybe a 1" shorter in dia prop so that you don't "load" the engine too much, and yes the same pitch as Fox (5"-6") pitch.
Glow plug try one with idle bar by installing it and SLOWLY turn the prop so that you will not have idle bar interefence.
Run it in like you would a Fox, somewhere in the area of 8200-8500 R P M, with adequate cool down between runs.
Hope that this helps... y1
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Like Brother Gil said! A 10-5 or 10-6 prop, fuel in the 5%-10% nitro range with a minimum of 25% oil, mostly castor. Launch with the engine "cackleing", on th edge of a two stroke and 4 stroke.
Maybe a touch stronger than the Fox and maybe a touch less than the OS .35S.
BIG Bear
RNMM/AMM
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Thank you gentlemen for the advice. This motor looks like new and I am thinking of putting it on an Oriental
Again thanks for the help.
Steve Thornton
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Thank you gentlemen for the advice. This motor looks like new and I am thinking of putting it on an Oriental
Again thanks for the help.
Steve Thornton
Hi Steve,
I would run it on the bench a bit just in case it isn't broken in yet. Check to see that the rod is free on the wrist pin. They can lock up after being stored for a while, and then the rod will wear out to fast on the little end.
BIG Bear
RNMM/AMM
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Thanks Bill
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In the 1950's and early 60's I ran nothing but Johnson engines. Johnson's reccommendation for break in was to cut a 10 X6 prop down to 7 inch diameter and run the engine in a fast four cycle with that prop for about two quarts of fuel. Fuel should be 24-25% castor. I'm sure it would be OK to substitute about 3-4% synthetic for some of that, as suggested above, if you wish to keep things a little cleaner inside the engine.
Johnsons are reletively long stroke engines for flying will use slightly higher pitch props and lower RPM than most of the modern engines. Start with 10-6 for flying.
I had two of the Johnson Stunt Supreme's both in Noblers (Green Box) and they ran very well...much better than any Fox. Much more powerful and better more consistent runs.
My Butddy Hot Handle (Walter Weatherford) won one of them in a combat contest in (I think Wichita) around 1959 and gave it to me because he wasn't interested in flying stunt. I think I got the other one in a trade for a Fox Combat Black Head.
Wish I still had them.
Randy Cuberly
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Thanks Randy! That was the encouragement I needed. The engine belonged to my uncle/mentor and has a very sentimental value. I have an old Rev-Up that I can cut down.
Steve
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If yours is what's known as the Johnson J-SS 35 then I have an engine test done by Peter Chinn at http://sceptreflight.net/Model%20Engine%20Tests/Johnson%20J-SS.html