Have you checked to make sure the back plate, head and carb are all tight? Also put some fuel tubing over the needle valve where it enters the carb - this is a troublesome spot that can cause headaches.

Hogflyer

Hogflyer, Are you talking about the low speed needle? From the manual the low speed is the black screw on top of carb with a lock nut, is this right?

I hate to admit this, but I bought three of the evolution engines: a .40, a .61, and a 1.00. All did the same thing and i could not get any of them to run reliably, no matter what I did. Even the club pro was scratching his head over this (these engines). I even was ready to get an OS carb to see if that would fix it. But the carb was almost half of what a new OS would cost so I opted for a new OS. That ended my problems. Solution: get rid of the Evo's and get an OS or Super Tigre, or Magnum.. whatever... but get rid of the Evo.

DS.

Out of all the replies, guessing that 50% said that it would stall, deadstick not good. I can buy a different motor and send this one back to get fixed. Using it in another arf in the future if it ever runs right.
What's a good, solid motor?
1) OS 46 ax
2) thunder tiger pro . 46
or what else.

Both of those are ggod choices. The OS is the more expensive and MY personal preference but in all fairness, I've never run one of the others.

Is this the right os 46?
http://www2.towerhobbies.com/cgi-bin...&I=LXFMD5&P=ML

Yep, the good one.

One thing you should think about is if the fuel line is pinched or taking any excessive turns or bends.

Ok so i went to the field yesterday to see if i had fixed my problem. Nope the darn thing is still cutting me out and it is really annoying me, it sits there at idle for a few mins fine, taxis out fine then as soon as im on the strip and give it full power to take off bam the motor goes to die, u can save it by backing the throttle off to idle right away. Also i have had a few very low level dead sticks into long grass because of this which is annoying. If a few of us are having this problem it leads me to believe there maybe a problem with some of these motors. I have tried all low and high speed needle settings to no avail!!

BUY A OS ENGINE PROBLEM SOLVED

Yup it's not tuned up properly. I've been through all of this on my PTS and .46's... all of which are running reliably now.

Make sure that:

- You do not have a cut or nicked tube anywhere. This can often hide from you.
- You perform ALL tuning with only 1/3 of a tank in the plane
- You remove the limiter pin so that you can turn the needles past the stop
- You do something about the infamous "needle walk" on the Evolution engines.


Needle walk: Once warm the needles tend to "walk" with engine vibration. A little locktite and tightening of the clip helps a lot.


As you throttle up note HOW the motor tends to die. This will help you pinpoint the problem.

Does it get sluggish, then slows and dies?
Or does it die almost immediately as if you threw a switch to stop the engine?

The former means that the engine is too rich, the later too lean.

The low speed needle setting affects the engine through most of the throttle range, so if it dies or goes sluggish and then dies, before it every gets to full throttle at high revs, the low speed is off.

Run the plane up to about 70% throttle with 1/3 of a tank, then do the pinch test.
Nose the plane up in the air, and make sure that it does not die (it will speed up as it leans out).... then nose down and make sure it does not die (it will slow down as it richens out)....

If you can get this somewhat reliable, take it back to idle and try gunning the engine back up to 70% several times to observe the behaviour. Does it cut out?

If not move to the same tests at full throttle.

Pull the ol High speed needle off an try a diffrent one. The field trainer(nexstar)had that same problem. Pulled a needle off of another airplane an it ran like a top. If you get it going you won't find a more dependable engine,Well its hard to beat an OS. But they are good lil motors , little behind on the power but still good....................Did you assemble the highspeed needle?

Ok, thx guys ill try that tmoz when im back at the field, gonna maiden my funtannax50 with saito 82 too, yewww

I get it tuned pretty good where it responds clean and strong but dies after running a high rpm for over a minute. I was thinking if I should get a new hsn assembly. Horizon said to ship the motor back to them, will having taking the limiter off affect the warranty?

The low speed needle is the screw inside the blue limiting collar. If you want to adjust it you have to loosen the small allen screw on the collar first.

Horizon told me one time that the factory settings were 1 1/2 turns out on both high and low needle settings.

You loosen the allen on the blue collar(lsn) correct?

Yes loosen the allen first, then use a small flat blade screw driver to adjust the needle. This needle is pretty sensitive to adjustments so once you have adjusted 1 1/2 turns out adjust in small increments. I had to lean mine (turn the screw clockwise) just about 1/8 of a turn to get a smooth transition from idle to full throttle. Once I had it in a good spot I set the collar in the middle of the limiters and tightened it back down. Once you get it right make sure when you're moveing the collar that you don't move the needle again by accident.

I had problems with my evolution trainer motor when i got my first plane. Got help from someone who i thought had experiance in rc planes. Problem is he wasn't familiar with the evolution motors. We both thought it was running fine. I let him take it up but it died just after take off . I repaired it strugled and strugled to get it running well crashing a few more times ( not much damage). Then broke down went to a local club. Guy there wound the needles past the limiters and started from scratch. He had it running like a swiss watch in about 10 min. I let him test fly it for me , all went great. Ive been able to go months now at a time needing little too no tuning. I now have 2 evo 60's that ive had better luck with. and the evo pts still runnning well. I still need advice from other's at times when it comes to tunning though. Not saying there isn't something wrong with your motor , im not sure. Just saying might want another first hand opinion. Good luck. PS ( borrowed a 46 os AX from my brother, don't think ill give it back. im going to buy another to replace it)

Dying after a while at a constant throttle setting tends to indicate that the air/fuel mixture is overly rich at that point.... which goes hand in hand with your other observations.

You may need to lean out the high speed a bit, then go back and work on the low speed, which will then be off again.

It got up to 40 today so I gave it another try. Went back to stock settings, and leaned it from there. I ran the engine quite awhile one time without it stalling. Still working on it though. Looks like just a tuning problem, which should be easily resolved when warmer. To those with the evolution, the pin on the lsn blue collar rotates back and forth, what does this do?

That blue collar with the pin on it is the limiter for the low speed mixture adjustment. Get rid of the pin and the collar. I have yet to work with one of these engines that is set correctly on the low speed limiter. If it on the H9 P-51 PTS, that pin has a tendency to hit the cowl when you throttle up, causing the low end mixture to be set to its full rich limit, causing idle problems again.

Brad

Like Bkdavy said!

However it is not necessary to remove the blue aluminum collar...

Grab a pair of pliers and PULL the pin itself from it's socket. It will come out.

The collar provides some additional friction helping to prevent the needle from moving. While it doesn't do a great job, removing it is not necessary.

When I turned the blue collar, does it affect the mixture? Seemed like it did.

The blue collar is attached to the low speed mixture adjustment. Turning it clockwise will richen the low speed mix. Turning counter clockwise will lean the low speed mix. The pin sticking out of the collar is the limiter to prevent the user from turning it past a certain point. Therefore, removing the pin will allow you to make a broader range of adjustments to the low end.

Brad

This is taken from the evo manual, also here is a link to manual
http://www.horizonhobby.com/ProdInfo...inesManual.pdf

Low- Speed SetRight Needle Valve Correction
Should the low- speed SetRight needle valve
need to be adjusted outside the factory-
established parameters, follow these steps:
A. Loosen the setscrew found on the ring of
the SetRight assembly to which the
adjustment bar is attached.

B. Rotate the needle valve itself (small
slot- headed screw inside the blue ring of
the SetRight assembly) clockwise to lean the mixture or counter clockwise
the mixture as desired.

C. Retighten the setscrew on the ring of
the SetRight assembly and you have
re- established a new range of motion.