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Old 02-16-2015, 05:55 PM
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What props and rpms are expected?

Tony
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Old 02-16-2015, 06:15 PM
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I will be trying a 24 8 beechwood xoar, a 24 8 laminate xoar then onto the heavier 24 10 mejzlik and 25 8w falcon.

Nothing is expected performance wise as I have no idea how this motor will perform, I would like it to beat my EME 60,s though. I would hope it will come close to a 70 twin I supose.
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Old 02-16-2015, 06:50 PM
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I would like to see more support in the cylinder for the piston.not a fan of skinny fingers,everthing else I like.


and I bet it will make more power than a 70 twin.
but it might be a thumper.being a larger single.
so who is selling these engines?
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Old 02-16-2015, 07:34 PM
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Quote:
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I would like to see more support in the cylinder for the piston.not a fan of skinny fingers,everthing else I like.


and I bet it will make more power than a 70 twin.
but it might be a thumper.being a larger single.
so who is selling these engines?
It has a solid cylinder wall with a port window where the piston skirt contacts the cylinder opposite the exhaust port. The engines that seem to have problems have finger ports in that area.
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Old 02-17-2015, 12:26 PM
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Today did not go to plan, got to the field and got the DJ 72cc running no problem but for the life of me I could not find a tune.

Horrendous surging on the top end made it impossible to find a peak rpm, tried the needles everyway possible to creep up on a usable setting but no luck, somethings not right. It did start easy every time, transitioned perfectly and ran well through the midrange (at least on the bench) but as soon as full throttle it just surged, this was on the 24 8 beechwood, the 24 8 laminate and the 24 10 mejzlik.

Was running it on a old rcexl ignition and not the supplied RCAME ignition due to my old ignition having a tach output and the RCAME has not so next time out I will try the RCAME ignition just incase my old ignition is failing at high load. Will also take a 55cc carb and try that if the ignition makes no difference, might choke the motor rpm a bit but at least if it tunes I will know where the issue is.

Not exactly the post I was hoping to make today and unfortunately now have more questions than answers on this engine, there is hope as it did run well apart from the top end and although hard to gauge power the way it was running I would say it at least matches the EME 60 for power, though unfortunately at this moment in time runs nothing like as well.
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Old 02-17-2015, 01:19 PM
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If you were running a different ignition battery on the bench, than in the plane, I would look there too. I had a 50cc engine that was driving me crazy. Seemed like no needle setting would make the high end run correct. I finally traced it to a weak (I thought was good) ignition battery. It sounds so much like needle setting, but was just the battery not up to snuff powering the engine at high throttle settings. Start, idle, mid...everything good until I ran it up past a certain point.
Bill
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Old 02-17-2015, 01:41 PM
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Teflon is a fluoropolymer
Yep, I stand corrected, key word is polymer, which is "plastic".
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Old 02-17-2015, 01:57 PM
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They're get'n lower mate.....
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It is the tetra which relates to 2 three compounds joined together in paralell within a poly (2) structure
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Old 02-17-2015, 02:02 PM
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Quote:
Originally Posted by Badams View Post
If you were running a different ignition battery on the bench, than in the plane, I would look there too. I had a 50cc engine that was driving me crazy. Seemed like no needle setting would make the high end run correct. I finally traced it to a weak (I thought was good) ignition battery. It sounds so much like needle setting, but was just the battery not up to snuff powering the engine at high throttel settings. Start, idle, mid...everything good until I ran it up past a certain point.
Bill
Tried another ignition battery when at the field so thats one thing I ruled out, good thinking though.
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Old 02-17-2015, 04:51 PM
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Originally Posted by Truckracer View Post
It has a solid cylinder wall with a port window where the piston skirt contacts the cylinder opposite the exhaust port. The engines that seem to have problems have finger ports in that area.



thanks for pointing that out, now I see it after going back and looking closer at the pictures.
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Old 02-17-2015, 08:39 PM
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Yep, I stand corrected, key word is polymer, which is "plastic".
are you still making the da 70 baffles. for the rf 91" extra.?
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Old 02-18-2015, 06:49 AM
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raydar, where did you buy your engine. or are you just doing the testing on it for the manufacture.
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Old 02-18-2015, 10:38 AM
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Could have an air leak after tearing it apart.......
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Old 02-18-2015, 11:04 AM
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Could have an air leak after tearing it apart.......
Only had the jug off and it's sealed fine, never split the crankcase. I really need to try it on the supplied ignition and another carb before any conclusions are made.

Got the engine direct from DJ engines .
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Old 02-18-2015, 02:12 PM
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are you still making the da 70 baffles. for the rf 91" extra.?
Yes, but I have been off line for a few months now. It turns out the issue was a shorted wire harness to the Y axis stepper motor.
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