new evolution .61/Alpha trainer dude

Yep, I'm one of those lucky guys who's wife put the trainer package under the tree. This is my first glow powered aircraft, though I've been flying gliders for a few years. I put it on the bench in the garage and it would not fire up. It would run for one second then quit. I fiddled with the screws, trim, and throttle and finaly got it to run at a fast idle. Any throttle change and it would quit. So I loosened the slow jet screw, gave it a few turns and it fired right up!

So now I can't stop it. With throttle closed it keeps running at a fast idle. Also, top RPM is reached at 3/4 throttle, any more and it slows. I think it is running way rich. How should I proceed? I live at a mile above sea level, that may be a clue to ya'll. Dan Cutter. ps, the plane is lovely and what a deal. $299 for the whole thing, radio, engine, etc. I see at Tower it is over four hundred, think my local hobby shop made a mistake. He He for Me.

Reply to
dancutter
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Should be an engine break-in manual somewhere in that box!

If no manual then the basic break in procedure is to run engine rich as possibly in order for the engine to keep from stalling! You need to run at the very least, 6 or possibly 8 full tanks of 15% Nitro Fuel. After each tank full let you engine cool down. Also turn your mixture screw in @ 30 degree intervals for each tank full. During break-in you'll hear the engine surge up and down - sound may change a bit. Don't be alarmed as this is normal. Once you engine is properly broken in. You will need to adjust your fuel mixture screw as well as your idle screw. 1st you need to (have a buddy hold in place) secure the plane from flying away! Next - Start your engine - Set the idle screw a bit high - next do a full power @ the same time turn cw or adjust the fuel mixture screw to obtain optimal full thrust/power. Then throttle back to idle position. If it stalls you will need to re-adjust mixture screw. If no stall then re-adjust your idle screw to lowest idle setting and then back @ 1/4 turn cw. Test again to Full Power and back to Idle several Times. When you're sure that the engine isn't going to stall. Re-fill the tank and be safe - don't friggen hit anyone

You can stop the engine by plugging the exhaust with a rag or if you don't care if you get burned -- use your thumb!

umm -- well gee - yeah you will have to run a bit rich I have a cabin out here (am here now) @ Big Bear Lake, Cali. Is @ 6000+ feet and friggen burrrr cold-was snowing last night.

BBA

Reply to
BBA

IIRC, the Evolutions are pre-run in at the factory, and you shouldn't need all that much break-in. Look at your exhaust. If it spews out lots and lots of oil and unburned fuel, it's too rich. However, if it sags at wide open throttle, it may be too lean and may be overheating. The trick in breaking in an ABC engine is to run it wide open and lean the high speed needle till it reaches maximum rpm, and then richen a few clicks. Let the engine run only for about three minutes, then shut it off and let it cool down. Repeat until you have a smooth, consistent idle.

The run-at-fast-idle problem might be caused by an air leak. Make sure you have a good seal between the carb and body of the engine, and that all your backplate bolts are tight. Some folks like to use some silicone sealant or RTV to seal these areas. You can check your low speed idle settings with the pinch test. Block the fuel line by pinching it while the engine idles. If it speeds up significantly and quits, it's too rich. If it dies without speeding up, it's too lean. You want to hear it speed up just slightly before the engine dies.

Morris

Reply to
Morris Lee

The evolution engines need no breakin. They are prerun at the factory. Every evolution engine I have seen has run great right out of the box. And don't run it overly rich. ABC engines like the Evolution need to be run just a bit rich so they heat up and the cylinder expands to the proper fit with the piston. Ringed engines need to be broken in very rich, but not ABCs.

Your best bet would be to find someone to help you.

John VB

Reply to
jjvb

You didn't see it at Tower. Tower is Great Planes. Evolution engines and Alpha trainers are Horizon products. Horizon and Great Planes are the two biggest hobby distributors in the USA, and they are fiercely competitive with each other. There is no way on God's green earth you'll ever see Tower selling Horizon products, unless Great Planes and Horizon merge.

Now, what did you REALLY do to the engine settings? The high-speed needle is the one you can turn by hand while the engine is running. The low-speed is on the side of the carb, and requires a screwdriver. Did you mess with the needle limiters? If you did, and didn't pay attention to the original settings, you might have the engine so out of whack that it isn't going to run right unless someone with experience tunes it for you.

The Evolution engines come pre-tuned and pre-broken-in. You do not have to run tank upon tank through the engine at blubbering rich settings. Blubbering rich is bad for an ABC engine like this one anyway.

Try this test: While the engine is at full throttle, pinch the fuel line. What happens?

If it speeds up, it's lean. Close the main needle more. If it slows down or quits, it's rich. Open the main needle more.

Reply to
mkirsch1

I feel like an idiot. I told you the wrong conditions for the pinch test. Let's try again:

Pinch the fuel line momentarily, and release. What does it do?

If it speeds up, it's RICH. Close the main needle valve more. If it slows down or quits, it's LEAN. Open the main needle valve more.

Reply to
mkirsch1

Thanks for your replies. I'll run it again today and make notes. As far as the limiters, it just would not run the way it was set at the factory. After an hour of trying, I loosened the nut on the slow speed screw and backed it out two full turns--that's all. Then it sprang to life first flip of the prop! I didn't mess with the high speed limiter at all. Since it would not stop running with the throttle closed, I then screwed the low speed screw in until a nice idle with the throttle just cracked. And yes, it spews a lot of oil and fuel!! I think that is due to my altitude and I'll adjust the high speed screw. I'll get back with the report if anybody cares to hear it. There is no break in procedure instructions, because the chinese already did it for me. Dan

Reply to
dancutter

If you opened the idle needle 2 full turns from the factory setting, your idle setting is WAY TOO RICH. The idle settings on most engines are adjusted about 1/8 turn at a time. The high speed setting is of course the one that can take a bit of tweaking. I would recommend you close it to just after the stop and try from there. The best recommendation would be to find your local club and get some help from there. As has been said, the Evo engines are prerun at the factory and should run out of the box. your altitude may play a role as you have said. Evo's tech support is also very good and a phone call to them will most likely have you running as well. I have 2 of the .46s and love them. If you have never flown before, please do yourself a favor and get with your local club and get an instructor. If you don't, I can almost guarantee that your first flight will last about 30 seconds ending with a crash. This hobby is way too enjoyable to get frustrated with not to mention the expense if you try to fly this on your own. You wouldn't expect to go to the local airport and climb into a Cessna or Piper without an instructor would you? Same applies here. Welcome to the hobby and I hope you find out just how fun it can be.

Jim W

Reply to
Black Cloud

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