Long time reader, first time “poster”, so please, be gentile… I have a Evo .45 TPS spinning a MAS 11x6, running 15% nitro, and I have tried just about all the plugs offered by O.S., and also the 2 and 4 stroke “super” plugs form Hangar 9. None of which will last more than a flight or two, and then there shot. I’ve had the “pro’s” at two local clubs take a look and quite a bit of time of adjusting the needle valves (high and low) and it still runs like crap on the whole. Do I have a dud motor, or is a FNG like myself just missing something here…. Any input at this time would be helpful, Thanks

Normally I'd say that you are using cheap plugs but the OS's, especially the #8's are great and normally last a long time. You mentioned 15% fuel, what kind? How much and what kind of oil is in it? Also, what are you using for a glow plug battery? It is possible you have an engine problem. I've seen a lot of Evolutions at the field that were a handful. Make sure all of the screws are tight on the head, back plate and carb. If the experienced guys at your field can't figure it out, I would make a call to Horizon and ask about having the engine checked out and repaired or replaced. Their customer service is always great.

how are the plugs failing? do they look "pushed in"?

That's what I was wondering. Are the plugs just going pop when you are trying to start the engine?? Are they giving up the ghost during the flight? Does the engine start and quit when you remove the glow driver? Are you using A clip on glow driver or A power pannel??
I have killed plugs using after run oil then starting the engine after it has sat A while but other then that my number one killer was putting the ends of my glow driver into the starter side of my power pannel. I have had plugs go out when I was getting that nasty gray metal stuff floating around in an engine that was wearing out.
Plugs burning out like that just isn't right, I can go forever on A OS #8.

I had all sorts of issues with the Evo series. I had a .46, a 61, and a 100 NX. The .46 ran well at first, but it too began to eat plugs, then it would not run more than a few minutes and would dead-stick on me. No one could figure out what was wrong with it. I eventually sold them all.

However, one key thing that I learned about them was that they really needed the correct mixture at both ends (high speed and idle) to run right. To lean, and they would burn up plugs. To rich and the engines would not run worth a darn. It takes time and patients, and determination because you are working at both ends.. mixture AND glow plug issues.

CGr

Are there metal particles in the exhaust residue?
When the 12 volt battery that powers your glow driver panel loses its' charge, the tendency is to crank it up to compensate and this will shorten plug life, too.
Air bubbles that develope during a flight in the fuel tank can contribute to the problem.
Sometimes problems like this can have more than one trigger at the same time.

I hate to hear you unloaded your Evo's.... You are right though. They are rather picky about the tuning, but once I learned the engine, I become a huge Evo fan instantly!

We don't have alot of details, but my guesses are:
You're running too much current into the plug from your glow driver
You're running too rich and fouling the plug
You're running too lean and overheating / burning the plug

You should be getting a season out of the plug. Do some reading on RCU for tuning the motor. Especially using the "pinch" method on the low end. Tune the low end first, then the high end. Play with it until you learn. It took me about six months to nail it down. Not sure what that's saying for me though.

A buddy at the field has a .46 Evo that runs smooth as glass. He uses an A3 plug and 15% Cool Power.
I run a Evo .61NT that'll sit and idle for minutes on the flight line, gas it and purr all the way up. I use a H9 Super plug and 15% Omega
Both have rediculous power for their size.

If you haven't noticed, I'm an Evo fan

My Evo became easier to tune after putting an O-Ring around the carburator barrel. They don't come with one, just a little metal washer on the inside. Big Evo fan.

There are a lot of 'if I knew then what I knew now' issues here. Unfortunately, that's the way it is. We often learn through our mistakes and problems and benefit from those o f others. In this case, well, 'if I knew then what I know now' sure fits the bill.

I sold the 100NX to a fellow RC'er, and a fellow RCU'er. He got it, ran it, and loves it. I could never get it to run right in spite of all my efforts. But, I found that I needed a little more patients. He ran it and played with the carb and got it to run much better than I ever could.

Ah, such is life. The O'Ring thing would have probably cured most of my problems with that engine. And, from what I understand, so would an $80 carb replacement... however, that would have put the Evo 100 NX in the price range of the replacement I chose, an OS 1.20 AX, which, I might add, ran perfectly right out of the box and still serves me well.

CGr.

Fuel - Byron fuel 15% nitro, 20 total oil

Thanks for all the posts; I’m still trying to get the needle valve situation figured out, if a damn plug would last! The plugs are “deformed” (don’t know if that’s the proper term) the filaments are either broken thru (this only happened once), or most of the time, the coils on the super plugs are pushed together or bent against the walls of the plug. I pulled the plug and borrowed a borescope from work, and there doesn’t look to be anything wrong inside the cylinder, no metal shavings, no rust, and no deformations to the head, piston or walls. As for the power panel, this has happened with my hot shot 2 rechargeable and I have an accu-glo Mk 2 that the heat for the plug is at half. I get a heat light, continuity is good, and it always starts and keeps running with a new plug. Only upon restart do I have issues getting it to fire. Now that being said, I have 15 landings on this thing, and only 2 were under power… I got real good at dead-sticking this thing real quick! It will run like a champ on the ground, but moving the throttles in the air has gotten to be a very dangerous proposition. It has not responded to throttle commands, cut it rpm’s by 4000 in level flight, or just randomly died! It gets frustrating for a new guy to get MABYE one flight, and then the engine gets me pissed off, and I don’t want to try and fly if I’m not in the right frame of mind, IM STILL LEARNING! Well, I’ll get off the soapbox for a while, but hopefully I answered a few of the questions some of you had, and thanks again for the inputs.