I recently purchased this Evo .46 and am having nothing but trouble with it. I have put it in my trainer (LT-40) and using the directions that came with the engine I cannot get the engine to idle and transition to full power or find the proper Lean/Rich mixture for the High Speed needle. I have even taken the restricter collar off the High Speed Needle and still haveing problems. Anyone have any ideas on this. Thinking very seriously about going to gliders (ugh) might as well get out of the hobby.

P.S. Sorry to all the glider flyers out there!!

"The probability of survival is inversely proportional to the angle of arrival. Large angle of arrival, small probability of survival and vice versa"

If ı was you ı would just goto my local hobby shop and/or your club. they can help you! there ıs a number of reasons
why you cant tune your engıne. Too many for RCU - go spk wıth someone ın person.

Well, you probably shouldnt have taken off the collar just yet... but thats no big deal. First, if you can, try to find where it was when you bought it. Then Fire it up. Run it full throttle for a bit and see what it does. If the transition from low to high power is bad, then play with the low speed needle, but be sure to turn off the engine first, that one is a bit too close to the prop for comfort. Also, in the instructions that came with the engine, it will tell you how to tune the engine to factory settings, which is a good starting point. From what you described, it sounds like the low speed needle, i had a similar problem with my Evo. .46, there is a little screw on the carb. which lets you create a new "range" for your low speed needle. But first, read how to put it back to the factory settings, which is something like 2 1/2 turns from the bottom... dont quote me on that, but it should say in the manual. Once you get that low speed needle adjusted properly, that engine is fantastic .... i'm surprised it gave you any problems at all because mine came ready to go, all i did was fire it up and flew.... no problems until about the 5th flight, but i forgot about high humidity so i just adjusted the low speed needle and it works beautiful .

I bet one problem you're having is caused by air leaking around the carb body where it slides into the engine. There is a thin O ring that's supposed to seal this but I have found that they often don't do a good job. This O ring sits at the bottom of the hole where the carb slides into and the ring sits against a thin black washer. The engine will have a hard time shutting off when you cut the throttle completely and it will cause idle and transitioning problems. There are several of us in our club who had this problem right out of the box.
First, you loosen the screw in the collar which holds the carb in the engine case. Then pull the carb out with a twisting motion. Next, coat the part of the carb which slides into the engine with an automotive sealant like Ultra Grey, Blue or Copper. Also, take out the 2 black sleeves which the carb mounting or collar screw screws into and coat them as well. Coat the screw too. Assemble everything back together and let it sit for a day. Remember you only need a light coating of sealant. you should notice a difference.

The EVO is a great engine which I think you will enjoy owning. It is well made and very reliable. I'm sure it's just a minor tuning that's needed and an air leak fix. Don't let these things turn you off from this engine. you will hear almost nothing but absolute praise for the EVO. I can't say enough about mine.

HAHAHAHHAHAHAHHHHAHAHAHHAHAHAHAHHAHAHAHHAHAHAH[sm=biggrin.gif][sm=biggrin.gif][sm=RAINFRO.gif][sm=RAINFRO.gif][sm=bananahead.gif][sm=bananahead.gif][sm=biggrin.gif][sm=biggrin.gif][sm=tongue.gif]

ui_fearmaite,

Some of the EVO 46 engines had issues even after redoing the needle valves and checking the "O" ring under the carb. [link=http://www.krcs748.com/evolution_engines.htm]Follow the instructions on this page[/link] and they will do whatever it takes to get it repaired for you.

I found that after mine would warm up it would go lean.

By accident I had flooded it and while trying to start it, it was spitting fuel out of the joint between the head and the cylinder sleeve just below the bottom of the head at the front of the engine, but this only happened after about 2 minutes of running on the ground. Evo repaired it and it has since been a very reliable engine (Runs as well as the 2 OS46AX engines I have)

JW is right. Most engines run on the low speed needle for 2/3 to 3/4 of the throttle travel. Most engine running issues are actually due to low speed needle settings being off. Adjust the low speed needle some. Sound like you are lean. Turn the needlecounter clockwise 1/8 of a turn at a time untill it idles well and transitions. Be sure to run the engine a full throttle for a few seconds after making any adjustments to clear the crankcase of any puddled fuel. Do your adjustments with the engine off. Good luck with your engine.

Mark Shuman