Hello, I am still new to glow engines and am having some tuning difficulties. I have am turning a Master Airscrew 10x6 prop. I use a OS A3 glow plug and I am using Cool Power fuel at 10% nitro. The engine is about 8 years old. I had a false start in the hobby. It has never been run till last month. I got it up and running fine b following advice in this forum. Here is the problem. It idles great and will transition to full throttle with no hesitation or sputtering. I have the WOT setting about 1/8 of a turn on the rich side. But at ¼ to ¾ throttle it will load up with fuel. While flying it will eventually flood out and quit. I have become very good at dead stick landings. If I open it up every so often it will clear out the extra fuel, but that is something I don’t want to have to do. Any suggestions would be appreciated. Most things I have read say I either have to compramise idle or WOT, or I am just stuck with what I get at mid throttle.

I assume you have the TN carb on your Webra 40. You need to make sure the barrel gap is small when carb is closed. Using a small screwdriver screw in the low speed needle all the way and backout 2 full turns. This sets the cone (mid range adjustment). Start the engine, let warm up and bring to about 3000 rpm. If the revs fall off the mixture is to rich so adjust in small increments ti 3000 rpm is held. My Webra 50 GT didn't require this but my Webra 40 GT did. It works. These are good engines. I also use that prop, that plug and that fuel so it is not the problem even though the engine is most likely ABN. Good Luck!!! Do you have the white copy of the Webra instructions?????

I don't have any paper work with the engine. That why I think I have been having so many problems. Ill give your instructions a try, That is the first time I heard this. Thanks a bunch. I was starting to get frustrated.

well darn it. I am still frustrated. By the time I get the idle screw lean enough not to drop my idle. It wont transition out of idle. As soon as I give it any throttle it just dies. If I crank it out about half a turn, I can get it to hesitate just a little in transition, and it loads up just a little at 1/2 throttle. Any other ideas? Am I just stuck or am I missing something. I tried to find Webra on the web. Do you know an URL? Maybe I can download the manual.

I took the carb apart. There was a bad O ring on the barrell of the carb. Ill get a new one and try again. Hopefully that was the culprate

You might take the high speed needle out and see if the mini o-ring is in good shape as well as the carb sealing o ring. While its out make sure the fuel path is clean. I take it you have new fuel and not 8 yr old fuel. Are you using a stock Webra muffler??? As you look in the carb does the smaller diam rod approach the center of the larger diam rod when closing the throttle?? It should. I always assume your fuel and pressurization lines are not kinked and not leaking. I got both of my Webras from Natl Hobby in Ga so I don't know of any URL's

Well I am sure that the neighbors are annoyed with me now. I have been out there for 2 hours tuning that thing. Everything looks fine, but I did a bunch of stuff just in case. I had a Dubro exhaust deflector on there. Basically is a short rubber hose with a 45 degree bend. I do have the stock muffler and it points straight back into the wing. I took the deflector off, just to make sure that wasn’t it. I put in a new glow plug. I re-ran the fuel line as part of it had a greater than 45 degree bend. Took my fuel filter out, just in case that was leaking air, although I couldn’t see any air bubbles. I took off my air filter. And did the O rings on the carb. I was sick of fiddling with it, so I did it all at once. Afterwards, it ran much better, but I am not sure which thing was causing problems. Could have been more that one thing. any words of wisdom on which of those things I should have and which could be hurting me. I do like the air filter and deflector. I live in the desert and sand really seems to creep into everything. So the air filter is nice. I don’t think the muffler is close enough to burn the wing. I am just lazy and would like to cut down on the clean up.
Thanks for the help. I wish the wind wasn’t howling right now, I could really test it.

Ah, you're running an airfilter on that engine... make sure you've got one with sufficient airflow and that the filter is not clogged with dirt. What type of filter body do you have in there? Fine dust can close the filter up even if you don't see a lot of dirt.

If the engine has breathing problems and you adjust the mixture with the high speed needle, it will load up in midrange...

I never knew you were running an air filter. I tried one of those on a flip-n-fly OS 25FX powered House of Balsa P-51D Mustang because it had no wheels and the engine was inverted (not good). I never use Tennessee-go-fasters like fuel filters, air filters, vent filters, exhaust deflectors. They cause way more problems and solve nothing. I do filter the fuel when pumped in the planes tank. I have an OS 46FX, ST 40, and Webra 50 GT that have hundreds and hundreds of flights and they still run like new.

Hi!
I never run a fuel line filter on the engine!! They can leak!
And never an airfilter!
Always filter your fuel with a small auto fuelfilter ( fuelfilters could be bought from an autoparts shop) put inside the fuel jug !
Never use a fuelfilter in-line at the carb on the engine!
What plug do you have ? Fuel?
Prop?

Regards!
Jan K
Sweden

I run an OS A3 plug. A 10x6 MasterAirscrew prop, and I use CoolPower fuel at 10%. It was a Dubro fuel filter, but I have removed all that stuff. After I get it flying good I might try the Exhaust deflector again. I really am lazy and the muffler points directly at the LE of the wing. I can just see the oil hitting that wing and getting spread over every where. I have the Dubro fuel system thing, that you put in the cap of your fuel jug. It has a fine wire mesh screen on the inlet. Is that good enough or should I use more. I could easly put a car filter in the line too. Won't the oil in the fuel clog up the car filter pretty quickly? Or do you need to empty it out everytime you fuel.

Oh, and before I forget, thanks again for all the help.