Debra
01-04-2007, 11:37 AM
Hello:
I have a Moki 2.1 glow engine in my Top Flite Giant P-51. The engine was broken in on a test stand, and has about two or three gallons of 5% nitro fuel through it. It is mounted inverted with a Bisson pitts-style muffler, 20oz fuel tank with a pressure tap from the muffler, 20x10 APC prop and an OS Type-F plug. My problem is that the engine wont start inverted. If I turn the plane over so the engine's upright, choke it three turns of the prop, then flip the prop three times unchoked, then attach a Radio South glow driver and backflip the prop it starts immediately. Do you have any advice to start the engine inverted, as it's a bit of a task to invert the plane, start the engine, and then flip this plane over while the engine is running. I've tried a Miller RC geared electric starter as well, but the Moki just wont start inverted. Thanks!
- Erik S.
Dear Erik,
Any time you invert a 2-stroke engine you can expect starting and/or idle problems. The plug becomes a sump into which the raw fuel can collect. 4-strokes are less susceptible due to the plug being offset. Be sure your starting battery is fully charged and the glowplug glows bright orange so it can burn off excess fuel. If it only glows dull red it will drown out.
However, in your case it may be not enough fuel. Choking the engine lets the fuel run back out of the carburetor rather than into the engine. After choking and flipping the prop, pull the plug and see if it looks wet or dry. If dry, give it a couple of additional chokes. It may just require five rather than three.
An alternate starting method is to not choke the engine at all. Just spin it with the starter and have who ever is holding the aircraft place his fingers over the exhaust outlets. Assuming you are using muffler pressure, this will force fuel to the engine allowing it to start.
You might want to try another direct drive electric starter. It might be that your Miller reduction gear starter is not turning the engine fast enough.
If an engine idles in the 1,700 - 1,800 rpm range and the starter only turns 1,500, the engine is not going to start.
I would appreciate hearing if any of the preceding solves the starting problem.
Yours,
Clarence Lee
(to write to Clarence, please email man@airage.com)
I have a Moki 2.1 glow engine in my Top Flite Giant P-51. The engine was broken in on a test stand, and has about two or three gallons of 5% nitro fuel through it. It is mounted inverted with a Bisson pitts-style muffler, 20oz fuel tank with a pressure tap from the muffler, 20x10 APC prop and an OS Type-F plug. My problem is that the engine wont start inverted. If I turn the plane over so the engine's upright, choke it three turns of the prop, then flip the prop three times unchoked, then attach a Radio South glow driver and backflip the prop it starts immediately. Do you have any advice to start the engine inverted, as it's a bit of a task to invert the plane, start the engine, and then flip this plane over while the engine is running. I've tried a Miller RC geared electric starter as well, but the Moki just wont start inverted. Thanks!
- Erik S.
Dear Erik,
Any time you invert a 2-stroke engine you can expect starting and/or idle problems. The plug becomes a sump into which the raw fuel can collect. 4-strokes are less susceptible due to the plug being offset. Be sure your starting battery is fully charged and the glowplug glows bright orange so it can burn off excess fuel. If it only glows dull red it will drown out.
However, in your case it may be not enough fuel. Choking the engine lets the fuel run back out of the carburetor rather than into the engine. After choking and flipping the prop, pull the plug and see if it looks wet or dry. If dry, give it a couple of additional chokes. It may just require five rather than three.
An alternate starting method is to not choke the engine at all. Just spin it with the starter and have who ever is holding the aircraft place his fingers over the exhaust outlets. Assuming you are using muffler pressure, this will force fuel to the engine allowing it to start.
You might want to try another direct drive electric starter. It might be that your Miller reduction gear starter is not turning the engine fast enough.
If an engine idles in the 1,700 - 1,800 rpm range and the starter only turns 1,500, the engine is not going to start.
I would appreciate hearing if any of the preceding solves the starting problem.
Yours,
Clarence Lee
(to write to Clarence, please email man@airage.com)