Saito .72....Cutting off in flight! Help - RC Groups
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Aug 05, 2005, 09:01 AM
Semper Fly--Pro-Bro #2095
Merkaba's Avatar

Saito .72....Cutting off in flight! Help

Ok..I dont know much about engines....I just like to fly. So a fews weeks ago it the guy at the field to help and everything seemed well. Then just a few days ago I was flying and I could tell the engine wasnt pulling cleanly And the key is that when I make a quick bank thats when it cuts off usually. I do remember it sounding like it revved up before it cut off. I dont have a tach so i go by ear. I tried to lean it out til it wanted to sputter....then backing down till it didnt sputter....then backing a few clicks again, keeping in mind the whole max rpm-500 type of approach. Any tips. I've never liked messing with engines because I seem to be able to get the needles out of wack pretty bad. What do you suggest my course of action should be? Thanks for any replies.
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Aug 05, 2005, 09:12 AM
S.A.D. member
ivanc's Avatar
You should richen the mixture, not lean it. Sounds like it was leaning out (rpm going up) before dying. It's always safer to run an engine richer from the optimum setting than leaner. Safer for the engine and safer for the plane as deadsticks are caused by lean, not rich running engines.
Aug 05, 2005, 09:15 AM
Semper Fly--Pro-Bro #2095
Merkaba's Avatar
is that so....hmmm. Ok. Thanks! Anyone else agree or what...??

I mean are there any tricks to setting it. I know its either go this way or that way more or less. But I seem to overshoot sometimes. Oh well. Thanks
Aug 05, 2005, 09:19 AM
Equinsu Ocha
Lightnin's Avatar
Sell me your .72 cheap and go electric?

Now seriously,

You need to get over not wanting to muck with your engines if youíre going to pursue this hobby long term. Itís really not that hard if you take a pragmatic approach go things step by step. There are a great deal of things you need to tell us if we are really going to help you. Like what itís installed in, is it sideways or upside down installed, have you checked all the lines for leaks, is the engine center about even with the center of the fuel tank. Have you tried changing the glow plug, what kind of fuel are you running, what is the prop you are using. How old is the engine, have the valves been adjusted, etc. etc.
Aug 05, 2005, 07:01 PM
Semper Fly--Pro-Bro #2095
Merkaba's Avatar
yea I was kinda sleepy after working twelve hours third shift this morning so I wasnt thinking too clearly.

Its mounted upright in a .46 Ucan do. Pretty even with the fuel tank. Now the guy I bought it from did tell me he had the bearings replaced once before because he hadnt been using afterrun oil and they seemed to have gotten a little rusty. Before the past couple of flights it was very relieable. It always seemed run rich or not at far as I see it because the exhaust would be very full of fuel. I did mean to check the tubes because I had seemed to be running out of fuel fast. But when my buddy readjusted it and got it to fly without deadsticking, my usual flight behaviors and flight times returned. But I will check the lines tonight. Havent tried changing the glow plug, and I'm pulling a 13 X 6. Usually on Wildcat 15%

Thanks for the help.
Aug 05, 2005, 08:13 PM
In Massive Debt
Still sounds as if you need to jsut richen the mixture......BTW The best prop for the U-Can-Do would be a APC 14x4w IMO. The tank isnt moving in flight is it?

The fuel clunk isnt getting stuck in the corner of the tank?
Aug 05, 2005, 08:39 PM
Equinsu Ocha
Lightnin's Avatar
Seeing that you have had all that preventative maintenance lately, I would; check the lines and the tank, pull your glow plug and carefully apply power to it and make sure it glows bright red and replace if not, and then follow the directions in the link I provided and re-verify that the engine is set up correctly (the info in the link is like a cook book hard to screw up). And give it a try; if it still gives you trouble then start looking other places like valves out of time (do you hear any loud clicking)? Best of luck.
Aug 06, 2005, 08:19 PM
Semper Fly--Pro-Bro #2095
Merkaba's Avatar
no clicking, havent heard anything out sync or anything else abnormal. Just been sputtering a bit.

Ok, thanks. I think I have a 14 4, been too lazy to switch it out. Still havent checked out the lines. I'll try to get around to it and post again soon.

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