donnspadbauer

My Feedback: (26)

Alright you veterans, engineers and other glow GURUs who love some help poor farm boys with the fly bug.
I have two Magnum pro 45s on a scratch built twin spad and I think I have a case leak on one of them, #2.
Symptoms: Slow to rev but gets there and sounds fine
Slow to slow down and then plateaus at 4-5k(real real high idle) for 15 to 20 sec then down to match other engine at correct idle rpm
Throttle cut, idle down, and plugging the intake all produce results(read NOT a carb leak)
I bench run these and except above good running with lots of thrust. Adjusted to have maximum reliability(NO FLAME OUTS)
So I put er up for the maiden and Wow she climbs like a monkey, little left ail trim and good flyin, 10 seconds later....... dead #2 engine [:@][:@]throttle down around
she comes and down she sets it the ruff with only a broken prop on #1

Any Help or advice oh sages of nitro?

w8ye

My Feedback: (16)

Normally, slow to settle down to the finale idle speed is an indication of a rich idle setting.

Likewise, slow to spool up, indicates all loaded up with fuel from being at rich idle.

Quiting in vertical indicates a lean condition. Try pointing the nose up while on the ground to see how the engine responds?

Enjoy,

Jim

Flyboy Dave

My Feedback: (21)

Jim has the carb stuff down pat for adjusting for those types of symptoms. [sm=thumbup.gif]

However, if plugging off the carb shuts the engine down, and neither the carb
or carb flange is suspected of leaking....the next suspect area would be the
front bearings.

FBD.

wisdom-seeker

Since the crankcase is part of the system that pushes fuel/air into the cylinder, a case leak would normally prevent the engine from performing well. Usually this is because the fuel mixture gets too much air making it lean. A big enough leak, and the engine won't run at all. If you want the engine to behave reliably, fix the leak.

Kaos Rulz

Have you inspected the back-plate for tightness? Might want to seal this with a little RTV. I do that for all my engines.

RC-Captain

You will know if it is a leak , if you see excessive castor and fuel where you normally don't.

.............darn OS.40 crankcase. [:@]............