Mark071704

I have a magneto Zenoah G26 on a Giant Stik. I bought the plane used from a club member. I put about 30 flights on it and now I keep getting a dead stick at random times when I drop to idle. So far I have replaced the carb to a high performance one recommended for these engine (walbro wt-257) and swapped the coil and magneto off my g23 along with changing the head gasket and that didn't fix the problem. I also replaced the fuel tank with the same exact roto tank, new fuel lines, new t-fitting, and new spark plug. Engine runs great on the ground with perfect idle and transition but once I get her up and warm then let it down to an idle it dies right away. We have tried tuning it for over an hour leaner and richer with nothing solving the problem. Has anyone else experienced this? A fellow club member is selling me his g26 brand new sealed in the box. I am at the point where I just want to sell my G26 and my used G23 to pay for the new G26 I am getting from a club member. I have the same engine and setup on my Sig Four Star 120 and that engine runs flawless.

ahicks

My Feedback: (2)

If it's making take off power and flying OK, causing an issue only when you land, I would almost guarantee it's lean on the low speed. Especially if the area you're flying in has cooled quite a bit since the carb was last set up.

larry@coyotenet

My Feedback: (21)

Check for a crack in the carb insulator block, use a strong light as they can be hard to see. Very common cause of your problem, usually caused by over-tightening the block and carb bolts. allows the engine to suck air and go lean at idle.
Larry

ahicks

My Feedback: (2)

That's a good thought as well!

Mark071704

I checked the insulator block and it was fine. On a positive note I installed a brand new g26 today and the giant stik is back. No more dead sticks lol. I think I am just going to sell the other motor. Thanks for the input everyone.

CK1

My Feedback: (60)

It sounds like a crank seal is leaking and as things losen up when hot your losing crankcase vacuum through the seals and its going lean when at hot idle . It's an easy and inexpensive repair , basically gaskets , seals and bearings . I would also check the piston ring end gap for ring wear while it's apart.

H5606

Mine doesn't quit in the air - at least not yet - but with same magneto equipped engine on a high-wing model turning a 16x6 and gas/oil mix at 50:1, it sometimes quits on the ground when at prolonged idle and advancing the throttle.

With engine sitting idling on the ground for some period of time, it sometimes slows down all by itself; is this evidence of a lean or rich low speed needle setting?

CK1

My Feedback: (60)

Usually slowing during idle is associated with being rich . Does the engine bubble on acceleration after a prolonged idle? If so its a little rich. A lean condition would usually initially be a higher idle and the engine would hesitate and or quit on acceleration .

H5606

Thanks very much for the help.

I think so as I find I need to cycle the throttle mid-range a few times when advancing after prolonged idle -

Does this mean a rich low end (within reason) probably shouldn't quit?

CK1

My Feedback: (60)

A rich low needle is healthy as long as it doesn't load up too quickly at idle . If it will idle for a several minutes before it loads up and quits it's usually considered acceptable 👍