I say that somewhat tongue in cheek. I did search and read some posts but did not see a clear answer to my delimma.

I have a 40LA and it did run fine for a while. I hadn't flow for a bit and now everytime I get the plane out, it is the same story. Hard to start, gets tuned on the high end ok, pull back on the throttle to even halfway and zip... dies. It doesn't matter if it is cold or hot. Anyone have a clue on the culprit?
Thanks
Robert

I would suspect fuel or glowplug condition in that order.

The LA series are pretty dependable engines.

Good luck

Engines are bad about the back plate getting loose. Try tightening it and see what you get?

Enjoy,

Jim

Hi!
OS LA engines are very good and reliable!
Are you sure you have an OS 8 glowplug or an Enya 3...new one.
5-15% nitro, 5% is enough!
10x6-11x6 APC prop?
240cc tank (8oz)?
Use pressure from the silencer?
Set the engine a little rich.

Regards!
Jan K
Sweden

You haven't adjusted the low speed have you?

I think I have a new A3 os plug. it used to run well on K&B and then it would not. and now it doesnt work on this one. Is the plug the issue?

Hi!
Could be.
Get a new OS 8 or an Enya 3 glowplug...OS 8 is the standard plug for your engine.
Regards!
Jan K
Sweden

Glow plug? Air Leak? Out of Adjustment on low end?

I'd bet air leak--around the backplate as suggested above. I have two of these, and on one, I can't keep the backplate tight for over 10 or 15 flights....

Agree. It could also be a leaking cyl head (check the head bolts), & as noted by Cyclic Hardover, it could be the air bleed screw backing out, or accidently opened.

If you can find one, the metal backplate from the old OS 40 FP will fit your LA & it will peremanently cure the loose backplate problem

Thanks, I will check out those things

One more thing to check -- the NV O-ring.