Just finished a PC-9 of Seagull, the engine was inverted so it made the fuel tank's position quited high and cause flooding. Everytime I started the engine and taxi to the runway then the engne quit, and it happened again and again. Can someone help Please.

Edward

Once the engine is running, the fuel tank position shouldn't be so critical.

Not a lot of info to go on, but...

From the info you've given, it sounds rich, as it will idle for a few minutes then quit. I would suggest leaning the idle mixture out in small increments (1/16th turn) until the engine will idle reliably indefinitly. It sounds like you're close.

This is assuming that it is quitting while idling. If it is quitting when accelerating, then it might be too lean on the idle. If it stumbles while accelerating, but eventually cleans up and runs, it's too rich. Be sure to get the high speed mixture set close to optimum first, before adjusting the idle mixture.

An inverted engine is not the demon many people say it is, and can be made to run as reliably as any other engine. Been there, done that.

Dave

It would be helpfull if you told us what kind of engine you are talking about. Also If it's a long taxi you may want to try a glw plug with and idle bar. :^}

The engine I put it in is an OS 46 FX with OS#8 glow plug and useing 18% coolpower and 5% nitro. Just couple of weeks ago, this engine was used in an gp stick (arf) and it ran very well. Unless it is very critical when it is inverted. Pleased to read all those replies.

Hi Damnathius,

Thanks for your advices, it solved my problem and the PC-9 was ariborn th is morning for two flights. I turned the idle misture clockwise about 1/16 and it was much stable, but occasionaly it still quit. Do you reckon I should turn a little bit more in ?

Ed

Ed,

Don't be apprehensive about making further adjustments to your motor. Just make note your semi-reliable starting point so that if you go too far either way in your adjustments, you can return to what you had. Keep the increments of adjustment small and observe the changes in the engine's behaviour.

A tachometer is also helpful. If you are trying to idle below the manufacturer's idle setpoint RPM, you might always have an unreliable idle, and no amount of mixture adjustment will fix it.

Glad to hear your plane made it past the first flight.

Dave

Edd,

I have a PC-9 and what might be the problem is where your fuel tank is situated. As your engine is inverted your Fuel tank should be as low as possible otherwise if it is at the top of your plane the fuel will just run out into the engine and flood it. So try moving your fuel tank.

Thrust.

I realize all you smarter guys out there can get inverted glow engines to run well, BUT.... I've just found it enormously tedious and annoying to do that much tweaking, so much so that I just find a way to mount side or upright. While I concede that a glow engine can be tweaked to run well inverted, I would argue that the same engine with same effort will run BETTER upright. I fly several heavy warbirds, so I HATE dead-sticks!

mt

Everything I run is inverted. They're a little more touchy, but they will run fine. I have a couple of thoughts...

Fuel spray will work its way to the glow plug more quickly in an inverted engine and snuff out the fire if the mixture is too rich, or the plug is old or the wrong one. If you aren't running a new OS #8 in that engine, try it. It's an expensive plug, but may be worth it. This may help.

Also, if you can't adjust it out, and you can't move the tank for some reason, there is always a Cline regulator which will most likely fix it. At $50, it's a little expensive for a small plane, but I can tell you that once set up the engine will run awesome. I have never had a single deadstick with the Cline.

Good luck, Chuck