I was at the field saturday and I could not get my plane off the runway.

I would have it tuned on the bench. Ran at full throttle perfect, transition good, someone held it vertical and it would run good. Then as soon as I would start the take off roll it would die. It did this about 10 times untill I got tired of it and flew my other plane.

I replaced all the fuel lines. It will run fine, and took it to the road to taxi it and it died as soon as I advanced the throttle.

NOW, it is back firing![X(]. (at full throttle after it starts studdering)

I didn't know a glow engine would fire. I know it a regular engine that is caused by the timing being off. Does anyone have any suggestions?


Thanks,

Wings

If it does this going from idle to full throttle it might be too lean in one particular spot,mine did the same thing when it was new but it finally got over that.If you cant get it running call the factory and talk to the Evolution dept,there glad to help you get it running.Number is 800-338-4693 .
Good Luck

I have an Alpha trainer with an Evolution 40 engine and yes your way to lean. Richen it up about 1 full turn and see what happens. You never said how long you have had the plane or was it used before you. You also said you tuned it on the bench, it should have already been tuned from the company. Now I know I'm not a Super Member with over 900 posts, so please take my advice with a grain of salt. I ripped mine out with a 9 G negative inverted ground impact. I had to tear the whole thing apart, and built it back, During the build I had problems with it sputtering and dying on me and it was because it was too lean. Ran fine on the ground, but once I started going full it died.

Good Luck
Lefty
[sm=thumbup.gif]

I have an Evo .45 TPS engine, which some call a .40. It is a great engine that has only quit in flight twice. This was due to trash in the needle valve. I flushed it out with fuel pumped thru both ways. I collected a good bit of junk out of it. The engine has flown great since then. I have now removed the weighted flywheel and put a 11x7 Zinger on it. It pulls my Xtra Easy 2 straight up, almost out of sight, and it a very fast engine. Maybe you have had some nose overs in the weeds and sucked some debris into the engine? I would try to flush it out as this sounds like the symptoms that I had. I ran the fuel into a cup with a coffee filter to trap anything that came out, and a lot did.

Your engine is running too lean.

When you tune the engine on the ground you need to peak the engine (full throttle) where it will run without sagging or dying when the nose it pointed straight up and held there for about 20 - 30 seconds. THEN, open the high speed needle ABOUT 1/8 turn (or a hair more). This will richen the engine up. When you get up in the air (or taxing) the engine "unloads". This means the engine runs faster and leans out because the air going through the prop is being "pushed" by the motion of the plane - it has less resistance. You need to compensate for this on the ground.

It could be that the low end is too rich and the high end too lean or vice versa. Going from one to the other in a quick transition can cause all kinds of silly engine runs, and if you aren't looking for it, can give you headaches.

It does sound like you are too lean though. Even though you think it was set correctly, try setting it where you "know" it's well on the rich side. I often set student's engines really rich just so I don't have to think about it, or worry that it will be on the lean side in the air. It's rare that a trainer needs peak RPM anyway, so why bother with the headaches. I'd suggest backing out at least a half turn from where the needle is right now, ie a half turn from where you think it's peaked.

[link=http://www.rcuniverse.com/forum/m_1843103/anchors_1843309/mpage_1/key_/anchor/tm.htm#1843309]William Robinson advice[/link]

Thanks guys,


Above is a link from William Robinson that I think may have solved the problem. I didn't mention that I had the engine apart in this thread because I wanted a variety of answers to choose from.

I moved the sleeve slightly (only a bit) and reset the low end needle to exactly 1 1/5 turns from open and it SEEMS to be ok.

I taxied up and down the driveway, it didn't die or backfire. I just hope it don't change its mind when it gets on the runway this weekend.

Thanks guys!

I had a glow engine one time and when i took it apart i marked everything i could,reason is i wanted to get the sleeve back in at the same place,i even marked the rod/piston to make sure i didnt get anything back in and find out i had reinstalled it in the wrong position or backwards.I used a black fine point marker but that was a long time ago.
Good Luck

*i'm glad he told us he had it apart first* j/k