Thread Tools
Old Dec 30, 2012, 06:19 AM
ubihof is offline
Find More Posts by ubihof
Registered User
Discussion

G-Loads


Hi Guys,


Is there someone who can tell me how to fix a problem with my OS 40FX,

I have installed the engine in a home construction of an airplane built for speed, the plane flies very well, but I have a problem with getting my engine to run smoothly under G-loads, as long as i fly straight and level it spins like a dream, but when I make abrupt pitch changes or tight turns (High G-loads) the engine hesitates until I ease the stick and letting the G-load drop, then it is back in the zone in a flash.

The engine swings a 8x8 or 9x8,

Why is this ??. Wrong level of the fuel tank in relation to the carb is my guess but I don't know

Thanks


Ulrich
Sign up now
to remove ads between posts
Old Dec 30, 2012, 06:24 AM
gene6029 is offline
Find More Posts by gene6029
Registered User
gene6029's Avatar
Are you running a Jett bubbless tank? Sounds like fuel starvation. You might want to ask some of the pylon raceing guys this question.....Gene
Old Dec 30, 2012, 06:32 AM
ubihof is offline
Find More Posts by ubihof
Registered User
Hi Gene, thanks.

No just a regular rectangular plastic fuel tank with a clunck in it.
Old Dec 30, 2012, 07:08 AM
flyingscale is offline
Find More Posts by flyingscale
Registered User
I had that same problem when I flew a modified scat cat with a
Rossi as a power plant back in the day’s.
Ended using a setup with a pre tank kind of like a hili to get rid of air and have positive feed.
If it seems like the engine runs better as the tank gets empty id raise it up more.
I also have used a small ID line from last tank to the carb to reduce air and syphon back.
Old Dec 30, 2012, 10:19 AM
downunder is offline
Find More Posts by downunder
Registered User
downunder's Avatar
Try setting up your tank as a Uniflow which is simply done by having a clunk on the end of the breather line so it can follow the normal clunk feed to the carb.
Old Dec 30, 2012, 11:16 PM
kbozarth is offline
Find More Posts by kbozarth
Registered User
Quote:
Originally Posted by ubihof View Post
... the engine hesitates until I ease the stick and letting the G-load drop, then it is back in the zone in a flash.
Ulrich
Perfect indication that you are too lean. Open the high speed needle valve a few clicks until the hesitation goes away.

A Tetra or Jett bubble-less tank prevents this from happening. But for sport flying and entry level pylon racers, just open the needle valve a few clicks.

Kurt


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Sold ** RCLander 64mm BAE Hawk G/B Scheme RxR & LOADED ** Sammy70 Aircraft - Electric - Jets (FS/W) 5 Dec 30, 2012 09:49 PM
Losi xxx-s G+ loaded with tons of extras gac1983 Cars - Cars and Parts (FS/W) 0 Aug 26, 2004 02:09 PM
Question G-loading.... SpiritQuest Slope 0 Sep 01, 2003 04:28 PM