Well i had the maiden fly with my Avistar today. The very first flight the instructor took the plane and flew for 1 minute. He said i did a very good job balacing and trimming the plane. Anyways then I flew, he took off and all the rest of the flight i took control of the plane! I flew some rounds and made a very nice landing (alittle bit over the runway though). Then the third flight we were flying about 3 min into the 3/4 full tank and suddenly the engine stoped, my instructor safed my plane and landed safely and nicley at the end of the runway. Then the worst part: I was taking off and sudenly 5 seconds later the engine again stoped (Full tank), the instructor couldn't not fix it very much and the plane went down at a 30 degree angle into the ground. OK Looked at the plane (Though it would be destroyed) but no! Only a broken Propeller! Man was i happy!

Well all the people at the flying field were very friendly and I did not need to pay any money. Overall i really like the avistar, but the only problem is the engine, can somebody tell me what it could be that the engine suddely stops (LA 40)

-Nik

You will find that the avistar is a great flying plane. The OS40LA is a bargain basement engine. I would recommend that you step up to a OS46FX or a Tower 45BB

Well, since you already have the engine , a few things you might check,

check for air bubbles in the fuel line ,while running the engine up on the ground ,
If you find air in the line , check for tank Isolation (no Vibration or very little is what you want ,

check for air leaks around all the fittings on tank and fuel lines

check to make sure that your muffler is tight , a leak there will decrease tank pressure

there are other things but start with these and let us know what you find ??????

Highlander

Hi, I got an Avistar also and I maidened about 1 and a half months ago. I like it!!! It has the OS 40 LA on it and I never has experienced a problem with the engine. Two weeks ago, in midair I lost half of the muffler (the end part) but the engine didn´t quit!!! and I landed safely, even taxied back to my "hangar". I replaced the muffler with a Tower Hobbies 0.40 (without the baffle) and now it seems I got more power but I´m not really sure about this. Since the beggining I´ve been running the engine on the rich side so probably you can try this also. Following the instructions on the engine manual, close the valve slowly until you hear the "peak" on rpm´s then I open it about three or four clicks.

Good Luck!!!
Luigi

The LA series engines are also known to leak around the back plate, just pull it off and put some kind of sealant around it (very little will do) but dont over tighten the screws while putting it back together.
Mine ran fine at idle but at 3/4 to full throttle would spit and sputter or lean out and die. This was the only thing that fixed it.
It runs great and starts on the first flip every time now.
I spent more time flying today than most guys at the field because they had to tinker with there engine.hehehehehe

My Avistar /40LA combo was great. I'm still running the engine in a Superstar. Never a problem.
My friend however, had a consistent problem. He too had short flights. Engine would fail with no explanation. I would get a typical 18 minute flight. He would get 5 to 8 minutes. Same fuel, prop, tank size etc. He tried a bunch of different things as far as suggestions. Finally, we went back to chapter one, page one and looked over all of the basics from the very basic on up.
When it was discovered that the pick-up / clunk line was laying in the tank and not connected to the tube, we knew we found the problem. It's been flawless since.

Tim

I would certainly check all the above, but I would also consider that maybe the engine is running a bit too rich. You should run a new engine rich to let it break in. At the same time, running it too rich can cause the things to happen you are referring to, which has nothing to do with how much fuel you have in the tank. Conversely, it could be too lean as well, which would cause the engine to over heat and stop in flight as well. It could be one or the other, one of the other things mentioned above. it's certainly easier to make sure the engine is adjusted properly before you start tearing engines apart or tanks out. Your trainer would have to listen to the engine and adjust for the best setting. The point being, make sure you have someone who knows what they are doing adjust the fuel to air mixture. You will learn more about this as you go.

What you experienced is commonly referred to as a dead stick. Not good, but something we all have to deal with all too often with all glow engines. Some run better than others. Personally I like OS products. They just seem to run better and seem to be less sensitive to a number of things. IMHO.

I also had an Avistar what a great flying plane. I had the La .40 on the plane my engine never ran good at all every time i flew I would have to adjust the engine just to have it quiet 3 or 4 minutes into the flight I do not have problems w/ deadsticks on any of my planes after putting up with this for about 2 months finally i got sick of putting up w/ this (and finally got a job) so I bought a magnum xl .46 never had i had a problem with this engine it is a fine machine even after being nosed dived straight in from way high up when the wing on the avistar split in half for no apparent reason coming out of a low bank turn(allways fiberglass wings) I hated that so much.
after that engine i have had other Os engines the fx kind and have not Had a problem with them at all.

I had some problems with the 40LA in high humidity. I had the engine running fine for a month, than one day it was really hot. It had to be 90 deg F with close to 100% humidity. The engine died at full throttle. I noticed it was running lean. I opened up the needle, and didn't stall after that.

Since you nosed in, check to make sure the tank clunk isn't stuck at the front of the tank. That would easily cause the engine to die right after take-off.

You should also make sure the clunk line didn't fall off inside the tank, I've seen that happen, and the results are very much like what you describe.

I always check the needle before the first flight of the day. And if I notice something being "off", I do it again during the day. The air temp/density/humidity changes day to day and during the day, and that can affect your engine running quite a bit. Usually the changes are just a few clicks either way, nothing huge.