I mounted an engine on a plane recently inverted because of muffler clearance.

I'm having a terrible time getting it started...

I should mention that I use a fairly old glow driver. When fully charged, it starts eventually. It seems to just be flooded. What should I do with this situation?

I'm think of a power panel to adjust the voltage to the glow plug - since the glow driver seems to wear down quickly in this configuration?

Thanks.

I can probably help, but tell me... what plane... what engine?

Tower 75

Hangar 9, Cap 232

Ok, a two stroke... I'm not familiar with the tank location in the Hanger 9 Cap.

I agree with you, inverted engines can be a terrible starting problem. I just went through this...

A small drop of fuel settles in the plug itself, and its basically drowned until the fuel boils out or dries off. For some reason inverted 4 strokes are not as big a problem.

One solution: use a plane cradle and start the engine with the plane upside down, we do it all the time. Drawbacks, need cradle, awkward handling, can't fuel it upside down.

Another solution, pull the plug out after a failed start and replace with a new plug. You will actually see the drop of fuel in the old plug.

Another...... use a power panel and jack the heat way up after a failed start, it will boil the fuel out of the plug. You can try this on a plug you've pulled out. You'll get a little puff of smoke out of the plug cavity.

One of the best solutions... get a pair of surgical clamps, they are like a pair of scissors with a clamping surface at the tip. When you squeeze the handles together a ratchet mechanism keeps them closed. With the fuel line to the carb clamped off, fill 'er up. Then release the clamp just before you try to start, the carb will be dry until you start, preventing flooding.

These clamps are called hemostats and you can find them at http://www.scissorsales.com/hemostat.html

Here's what I did to solve the problem on my inverted Saito 0.91 in the new U_Can_Do 46. In this plane the tank is high, and will siphon into the engine, hopelessly flooding it.

I added a Dubro fueling valve (they seem to work better than the GP valve). I fuel the plane up through the fueling valve, which seals off the carb and diverts fuel into the tank. When I'm done fueling I pull out the fueling line and quickly stick in a clamped off stub line. This cuts flow into the carb until I'm ready to start.

I also thought about the things you mentioned.

A few guys helped me start the plane upside down - but then the pressure tube from the muffler gets loaded with fuel!

I will probably pinch the fuel line as you suggest and start the plane that way.

Thanks for the advise!

There are 3 tricks to learn with an inverted engine.

The first is that you have to get the fuel to run uphill from the carb into the engine when priming. I do this by turning the prop slowly with my finger over the carb until I feel it getting wet from fuel then roll my finger slightly to leave a small air gap and flicking fast at the same time. This gives a sudden jet of air that sweeps up the excess fuel into the crankshaft. Flick it fast a few times to get the fuel spread through the engine.

The second trick is knowing exactly how much fuel to spread through it. Too little and it won't start, too much and it'll be flooded putting out the glow or locking up with the risk of bending the conrod. Practise until you find the minimum necessary amount of prime.

The third trick is that when it's running the idle mixture has to be much more precisely set than you can get away with when upright. It needs to be just barely on the rich side.

Quite a few planes use fuel tanks that poke through a round hole in the firewall, centered in the engine mount. It's a good system and it doesn't hide any fuel tubing or connections in the nose of the plane.

Normally the result of this arrangement is a tank that is slightly below the carb level. Flip the engine inverted, and the tank is above the carb, leading to fuel flooding and siphoning.