I have the power trainer .46, never flown yet and it runs good for 1-2 minutes at 1/2 throttle then starts slowing down and suddenly cuts off. I'm running wildcat 15% nitro with 16% total oil and stock plug. My garage is 32 degrees and when I open the door it's 19 degrees outside. The needles are at stock settings and the tank 3/4 full. Could it be the high speed needle? When I open it to 1/2 throttle or better I don't see any bubbles going to carb but fluid coming from exhaust back to tank(drops of fuel?)

Hello John tammi

It sounds like it's running lean (not enough fuel). As an engine warms up it tends to lean out. Try giving it 2-4 clicks to the rich side after you get it started. This means open up the needle a bit. Try this first and let us know what happens.


Darren

You say "stock settings". Have you tuned it at all? It kinda sounds like its getting hot and quitting from being too lean. Garage temp being low helps but won't stop over heating.

BTW - I assume you meant Tower Trainer? Or the Evolution Trainer Power System?

Even though Evolution says the engines are preset, they often need adjustment and often beyond where the limiters will let you go. You MAY need to remove them to tune properly.

I turned it 1/4 rich on hsn and it did the same. I backflushed the high speed needle assembly and installed a filter between tank and hsn to catch any goo. I'll take the limiter off to richen even more if needed. Be back in a few. I took a temp and the highest was 170.
Thanks

Have you done "the pinch test"?

It did the same thing, took the limiter off and it was set at 1 1/2 turns out. Richening helped but eventually would still cut out. I'll do a search on pinch test.

Pinch test - basically can be done at any speed but usually done at WOT or idle.

Run engine to desired speed. Carefully reach in, beware of prop, and pinch off fuel line where it enters the carb.
If engine accelerates noticeably briefly then dies - too rich.
If engine just dies w/o increasing - too lean.
If engine accelerates just barely detectably - OK.
Test usually done first at WOT and then idle, adjust appropriate needle. Engine should accelerate smoothly from idle to WOT w/o stumbling.

Usually need to stop engine to safely adjust idle mixture.

I called horizon service and they said probably too cold and you would lean it to compensate for colder air, is that right? Would it hurt to run it that cold so I can do the pinch test?

I have one of those engines too and mine did the same thing but lasted for about 3 minutes into every flight then died! I even took the limites off and it still gave me trouble. Being a trainer and learning I didn't want to keep dead sticking it in. I finally changed out the engine to another one. A magnum .61 4 stroke works fine in my Alpha 40 trainer, I haven't had any trouble at all.

I had the same problem with my Evolutions .46. The first day was fine. But the next day it kept cutting out 2-3 minutes into flight. On the ground no problems after running for 2-3 minutes. I ended up ritchening it about 4 clicks and the problem when away. Contitions of flying site: I fly in Utah and it was a cold day and the elevation is 5000 ft. I also took the damperner out of the muffler just to see if it would help, at 5000ft we need all the power we can get.

Mike

Hold a hair drier or heat gun on the engine for a bit before starting. Once running, do the pinch test. It should work. People fly in those temps. WHY, I couldn't tell you.[sm=bananahead.gif]

I'll try it one more time today, thanks for your patience .

It was either this or do my job.

Ok. did the pinch test and got it right, least I think so. Got it to accelerate smooth and strong. Held it at 3/4 throttle and same junk, died.
Seems like others have had troubles with this motor, oh well my ignitor died anyway.

I had the same proplem with this motor, it would run at half throttle then die for some reason, then fire right up again first try. Hoping i have te problem fixed, i think it was sucking air at the needle valve intake. This was due to the refuling system that i was using pulling off slightly. I have adjusted and hope this will fix the problem. Does your motor do it at various needle settings and do you have a refuling valve?

Also make sure the carb is tight. Mine has loosened up before.

just what super said. i dont have the 46 but i do have the pts and it normally needs richening for flight compared to ground setting's. don't know if all engines are like this or just evolutions.

The motor would run at 1/4 or 1/2 or 3/4 or full and then just die. Richening did last longer till it died. I leaned it, richened it at 1/4 increments with the same end result. Tightened the carb just a tad.
I just found hopefully the culprit. The smaller diameter fuel line from hsn to carb has a tear in it at the nipple. I'll have to pick some up tomorrow and try again, what diameter is the smaller?

John, The fuel line tear is a definite indicator of a self leaning problem, You should be able to use medium size line. Also I noticed that you said it was 19 degrees outside. I was playing with one of my nitro trucks sunday and it was like 25 here in NJ. I have found a quick way to tune in very cold weather, Take the HSN very rich until the engine will run very fat at 1/4 to full throttle (Smoking and hesitating) bring engine to full throttle (should be very smoky with alot of oil from exhaust) slowly lean engine 2 clicks at a time until engine speed increases a bit. Move to one click a at time until the engine sounds a little smoother and rpms seem to come up. from there I go to the pinch method that Bruce descibed earlier, I usually make sure that I can always hear an increase in RPM's when the line is pinched. From there go to the LSN and do the pinch test and adjust for a 3 second increase in RPM then dies. Remember a little rich is always better.

I also had that problem that smaller line is rubbish, i bumped mine and it broke off leading out of the HSN, sounds like you may have the air sucking problem like i had, fingers crossed

Well, tried it again today when it was around 30 degrees. Running rich, full blast for about 1 minute and then die. Bringing it back to idle real quick when I heard it cutting out recovered it one time. It's like it just runs out of gas. Help!

Johntammi, does the engine run good/clean high revs at full throttle or is it sputtering and smoking before it dies?

Johntammii,

I am having the same problem with my evo .46. Runs fine all the way through transitions and then at full throttle it wants to stall after a few seconds. Even if i richen up the high end needle.

I put a new wooden prop on it with out balanceing it and i noticed a lot of vibration. When i took the prop off and balanced it, it was way of. Anyways, I am wondering if the problem we are experincing is a fuel foaming problem.

I haven't had a chance to run mine yet since i balanced the prop.

Iget it tuned pretty good where it responds clean and strong but dies after running a high rpm for over a minute. I heard that it might be the low end needle. I put foam under my tank, maybe I'll try it with the tank out of the plane also to see if that cures it.