Have a few misbehaving engines, and not the slightest how to repair them.

Waffleman Thu Aug 28, 2014 5:55 pm

So. I'm getting back into glow after flying mostly gas and electric RC for a while. And it seems that no matter what I do, my engines want to misbehave!

I have:
-An OS 52fs four stroke. Idles good, but the high end is unsteady no matter what I do. Its more of a reliability thing than performance.
-An OS 46la two stroke that runs hot. Really hot. And doesn't want to run reliably at all. I believe it may have been run lean previously, and am not sure if it can be revived.
-A supretigre 34 that doesn't want to run reliably, especially at high RPM.The needle is ineffective. It has pretty low compression for this type of engine.
-An OS 40SF. This one ought to run fine, but its missing the needle valve and the bolt that holds the carb on. It ran good the last time I ran it, but not sure what happened to the parts.
-Another OS 46la, this one the blue version. Its very worn out, and missing the needle assembly.

I only really care about getting the .52 and one of the .40s running.

Maybe one of you engine gurus know what to do with them.

getback Thu Aug 28, 2014 8:44 pm

WOW that's a mouth full there ....... First thing I would do is pick the TWO you want to work with, with good Compression and clean them good and start from there with a report back Very Happy

make it a little easier on trying to get some answers without a lot of conflict of intrest or just no involvement Huh...

Getback

pkrankow Thu Aug 28, 2014 10:29 pm

Pop the exhaust off, or at least swab with a pipe cleaner. Carbon and dirt buildup (and spider nests) can cause all the above symptoms - poor needle, no high end, excess heat.

If you can pull the entire engine easily give it a bath in fuel or denatured overnight. Popping the back plate is a good idea. Remove the needle and flush aggressively with a syringe. Swab out the easy stuff, blow the exhaust out, and bench test. This solves so many problems, and I am all about overnight soaks.

Phil

GallopingGhostler Sat Aug 30, 2014 5:02 am

Waffleman wrote:So. I'm getting back into glow after flying mostly gas and electric RC for a while. And it seems that no matter what I do, my engines want to misbehave! I have: [...] - An OS 46la two stroke that runs hot. Really hot. And doesn't want to run reliably at all. I believe it may have been run lean previously, and am not sure if it can be revived. [...] - Another OS 46la, this one the blue version. Its very worn out, and missing the needle assembly. I only really care about getting the .52 and one of the .40s running. Maybe one of you engine gurus know what to do with them.

You'll need the manual, http://manuals.hobbico.com/osm/40-46-65la-manual.pdf
Parts listing is found at http://www.gpdealera.com/cgi-bin/wgaprt100p.pgm?I=OSMG0047

Tower Hobbies has parts for the OS 46-LA. You can buy a cylinder / piston combination to repair the one, and a needle valve assembly to repair the other. You should be able to also swap parts between the blue and the plain aluminum colored versions, too to make one good one. Tower Hobbies: 46LA Piston & Cylinder is $37.99 per set. Needle valve is #40D. Parts Saver shipping is $2.

Regarding overheating, you can check the manual to see if the prop you are using is the correct one. Overpropping can cause overheating. A leaking head or glow plug, lean running can, too. You could have carburetor passages that need cleaning. Engines may need disassembly and a thorough cleaning. These engines are relatively simple, and you should get them back to good running condition.

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Have a few misbehaving engines, and not the slightest how to repair them.

Have a few misbehaving engines, and not the slightest how to repair them.

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Re: Have a few misbehaving engines, and not the slightest how to repair them.

Re: Have a few misbehaving engines, and not the slightest how to repair them.

Re: Have a few misbehaving engines, and not the slightest how to repair them.