Pascal
Senior Heliman
Location: Paris, France
| You do not have to use the Lotterle carburator, but I must say it makes the tuning of the engine VERY easy, specially on the OS91 which is not so easy to tune.
One of my friend was using an OS91 on an X-Cell helicopter and he had so many troubles that he switched to an YS80.
He is now using the OS91 Cspec with better success.
The problem he encountered were all about carburator, and even with the 3 needle carburator on both the OS91 and C-spec, tuning it was a difficult compromise between mid-range power, high range power and idling.
Using it with low % of Nitro was just making the compromise more difficult to reach, not to say impossible to reach, although a lot easier with the C-spec.
With the Lotterle carburator, when you order it you specify the type of needle you want in it. The default needle is the one which works best with 12% of synthetic oil and 0 to 1% of Nitro. But there are other needles available, should you want more oil and/or more nitro.
I am using 88% methanol, 12% of micromotul, and with this fuel tuning the Lotterle carburator was a dream : follow the documentation of the carburator, done, end of it.
I might have to lean it a little more now, as it burns its 15th liter of fuel.
In Europe, High % of nitro fuel are VERY expensive, and when I compare the power the OS91 deliver at 1650 rpm against the one of a Fury with a C-spec engine and 30% nitro at 1850rpm, I see little difference. Both can flip for ever without bogging their engine.
But there are two big ones :
My fuel cost me about 2.1 Euros per liter instead of >7 Euros for him.
I can barely hear my engine when he is doing 3D not to far from my Three-Dee NT
Pascal |
