I have a Zenoah G-23, less than 2 hours on it. Ran ok until yesterday. Now it primes well, fires, runs out the prime, and quits. Carb has been rebuilt. I've been advised to change plugs from the NGK that came with it. What should I use? Suggestions? TIA! Dr.1 Driver "There's a Hun in the sun!"
Check to make sure that the diaphragm hasn't been ripped. Sounds like it isn't pumping.
That's definitely a fuel feed problem so you need to start at the end and work your way forward. 1. In the fuel tank, is the klunk still attached to the feed pickup tube as well as moving freely? (sometimes, the tube in the tank can get stuck up in a corner). 2. Blow through the line from the carburator end and see if you get good pressure coming out of the vent tube (being a new aircraft, a piece of building trash might have got stuck in the line). 3. With all the lines hooked back up and with fuel in the tank, it shouldn't take more than maybe 10 hand props (with your finger over the carb opening) to get fuel to the carb. If it's difficult to get fuel up to the carb, you might have a bad diaghram or maybe trash in the carburator. 4. Related to #3, look for any place where you could be sucking air where you shouldn't be. Fuel tubing is cheap so try replacing all of it in the system just to make sure, check everywhere fuel tubing is attached, and see if maybe the carburator isn't tight to the engine and it's gasket isn't sealing (maybe trash under the gasket?). Also suspect ANY "in between" accessories like those cute little fueler gadgets ; I never use them because they're just one more place for things to go wrong. I use three lines to my tank (fuel pickup, vent, and fill tube which is really just another vent setup but the line instead goes to a 1/8" copper tube for fueling). Additionally, if the carb was rebuilt immediately prior to your having the problem, I would highly suspect that something wasn't put back right or sealed properly when it was put back together. There, now we've got your weekend planned :-) I really don't think the plug is the problem because if it's good enough to start the engine, it's good enough to keep it running more than just a spurt. Come back and tell us what you find.
MJC
"Dr1Driver" wrote in message news: snipped-for-privacy@mb-m05.aol.com...
Yup.
OK.
It takes 3-4 turns to get fuel running out the throat of the carb.
Good suggestion.
see if maybe the carburator isn't tight to the engine and it's gasket isn't
like those cute little fueler gadgets No filters or gadgets inline. Tank-filling line is separate.
I would highly suspect that something wasn't put back right or
Could be, but I'd swear I put everything back like it was. Besides, it was this problem that caused me to rebulld the carb.
I really don't think the plug is the problem I agree, but at this point, I'll try anything.
Will do, and thanks!
Dr.1 Driver "There's a Hun in the sun!"
Went thru a similar situation with my new G-23. Bench ran the new engine and all was fine, but not after configuring the throttle arm (with the carb off the engine). Once that was done and re-mounted, the engine had the same symptoms as you describe. Fought with it for 2 days -- called the dealer for help (and they misdiagnosed too), installed a rebuild kit, and still had the problem. Ultimately, another gas engine club member looked at it and found that I had the butterfly on the opposite side of the pivot rod when reassembling the carb. The screw that holds the brass butterfly has to be facing the piston. Turned it around, and the engine has been running fine since then. Make sure that when you look into the carb that you cannot see the head of the screw that holds the brass throttle plate.
As for the plug --- the NKG is a resistor plug, and most likely is just fine. The cross reference is for a Champion #4, but they usually have to be special ordered (at least here in NW In).
Hope you have it fixed soon, Rich
Damn! That could be it! I know on the G-62 I had, the carb had an air-bleed in the throat that the butterfly had to be aligned with. Since the G-23 had no bleed hole, I assumed it didn't matter. I'm gone to check it now! Thanks! Dr.1 Driver "There's a Hun in the sun!"
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