Model Forum / Radio Controlled / Helicopters / October 2008

you can run it at full throttle and it does not fly off at great
speed????  something is wrong if you can throttle it right up in the hover

Nitro is a little low.  You don't need huge amounts especially if you are
just learning but I'd try 10% maybe 15%.

Try to use fuel with synthetic oil as it will keep your engine cleaner on
the outside and less likely to 'gum-up' the internals.

But I don't think it's down to the nitro alone.

It sounds like the engine is bogging - assuming there is nothing mechanical
wrong with the drive or rotor head (too much pitch etc) I would say that
engine is running too rich.

If you run to lean then when you open the throttle quickly then it tends to
stop abruptly.  The engine will also get very hot - probably can't put you
finger tip on the back plate.

If you run to rich then when you open the throttle quickly then it tends to
splutter, become sluggish, sometimes even 4-stroke.  The engine will stay
pretty cool and you will be able to keep your finger tip on the back plate
indefinately.

It's hard to tell whether its the main needle or the idle needle you should
change.  I would go for the high needle because

(a) It sounds more likely to be the main needle.

(b) It's less sensitive

(c) It's easier to change

So you want to turn the main needle clockwise a few clicks at a time.  Don't
rush it.  Remember where you started so you can put it back.  Try it each
time you make a small adjustment.  Land. Repeat until it feels good.

Make sure there is always some smoke coming out of the exhaust - that's
shows there is plenty of oil looking after the engine - you don't need
clouds of it.

Check the engine backplate - if it's too hot to put your fingertip on for 2
or 3 secs then back the needle off as you are too lean.

Finally, register with www.runryder.com - very active forum with loads of
advice.

Also look here http://www.raptortechnique.com/

Cheers,

Nigel

When the muffler leaks you will loose fuel pressure (assuming muffler
pressure is providing fuel pressure) and go lean and get hot. Fixing
the air leak is the first order of business!
More Nitro will cover a multitude of problems because it nets out to a
broader useful needle setting.
The heli guys around here use at least 20%. With the rising costs of
nitro I can understand the desire to minimize it. I am also interested
if anyone is successful with that low of nitro content!
John Ferrell W8CCW