On my xcell, the 8 year old OS61 Not Wc, is behaving
badly.
Guy one, b4 me had 10 flights on her.
Sold it to me last summer.
I have tried and tried to get this engine running right,
but it runs hot and nasty at way to lean. (Only way
I have found to get power.) My bud busted my chops
for having so little smoke trail and tried to help.
But all I get is a 'SURGE' type situation.
3 needle carb, 30% nitro shoving 680's on the Sport
Trainer also 8 years of age, but low flight time.

The muff pressure tap is AT THE beginning of the
mainifold header right where it leave the cylinder B4
the silcone coupler up to the xcell minipipe.

At 3/4 stick and the hover, the engine surges and ups
and downs revs, will not develope much power and
I just can't seem to correct it with either needle!

Can anyone help me find this problem?
Byron

Replace the ring,it will run like new.

Paul:
What makes you think it's the ring?
I only have about 15 flights on the gal.
The guy be me had about 10 flights.
I wonder if he was unhappy with the engine
performance and sold it all to get out.
Did my half turn out on both needles CAUSE
the ring thing bing?
Shoot me some of your analysis!
BY

Not that it will absolutely fix your problem, but i changed the ring on my tired OS61 and it has way more power than before. It may be worth a try.

What M/A Minipipe? If you mean the upswept type header and hot dog muffler you might try some 15% fuel. That or get a simple Hatori (or clone) 60 sized muffler and keep the 30%. It sounds like the carb and motor are fighting the muffler. The non WC motor was harder to needle than the SXWC...but when set right flew fine! Chris

With the <OS 61 wcII though is the only one I've owned>you want the low end out about 1 turn, the mid range 0.25 turn or closed completely and the high end 1.5 - 1.75 turns open. (According To Which Pipe You Are Using Now)
Poor cooling system can result in engine over heating and a very rough run. This will usually show up with the helicopter running fine in initial hover, but it runs very rough after flying around a little (once it heats up some) Fix this by running the high end and low end a little richer (maybe 1/8 turn)
Settings on that engine could be totally different so set it with extreme caution mind you.
Enya #3 plug I believe works well with this engine.

Fuel, you want to run one that has at least 18% oil in the 15% nitro fuel and 23% oil in the 30% nitro fuels
As my wise ole Dad once said though, try it do not fry it. The ring idea sounds reasonable though....


I would scope out the piston & liner to chk. for large scratches on the side walls. Look for signs of unusual wear-check ring.

Thanks gents:
NOW i have something to look for!
I just didn't know where to begin.
Doc Reiss came up yesterday to our field
and mentioned he once had one of these older
OS engines, and he said the bearing design
was just a bit minimal. Hence the WC with
a bigger main crank set.
I am using 30% wildcat w/ 18% oil, and perhaps
this is fighting the pipe. (Upswept header, hot dog
type w/ silicone coupler.) Cul, we may be low on oil
according to your suggestion.
The ring idea is good, but it bugs me that this engine
is almost brand new, heck, I was really just breaking
her in! (But indeed, low 18% oil could have caused
too much immediate ring wear.)
We have one more nice day pred@65º here in NE today
so I hope the 15% nitro will work B4 I pull the engine
as the weather turns winter outside!
Any other ideas? Thanks a bunch! Better than encyclopedia UR!

Saturday PM nice weather, 64, no wind.
Took the xcell to the 15% nitro magnum tank.
Leaned out the high Needle to 1/2 turn out,
the mid to 1/4 out.
Fairly descent smoke, ran much better than
the 30%. It seemed to be 4 stroking before.
But, still had some power drop outs and tail wag
due to the engine revving up and down a bit.
About 60% better than it was however.
I am gonna pull the engine, and check it all out
and most likely do the new ring this winter.
Maybe the new OS70 is in her future...
Thanks for all your advise.
These XCell's are certain fine machines!