Problems with Evolution 45GX (not gx2)
 

I have this engine mounted on the GP Yak-54. Haven't flown it in about 8 months. Still had 1/4 gallon left of the break in fuel. It would take forever to start when it did it seemed to run fine. Last time I ran it was a week ago (prior to that.... 8 months).

Today I had some extra time. First thing I did was chunk the old fuel. Looked like varnish coming out of the can. Got some fresh fuel. Mixed it 35:1 with synthetic oil. New plug (Autolite compatible with the Champion RDJ8J which is compatible with the Brisk plug). Drained the fuel system completely. Put the new fuel in. Full choke, flip, flip, flip, fired....choke off, flip, flip, started right up. Little rough when clearing the air from the fuel line but came right up to high rpm's. Ran that way for about 30-45 seconds then the problems started. The engine started cutting out. I am not talking sputtering, I am talking completely cutting out for like 1/2 second at a time. It was doing this at all rpm's best I could tell. I tried adjusting the low speed needle but with no significant change. Finally put it back where it was per the manual (2 1/2 turns). I replaced the plug again with a new one just in case..... no improvement.

One thing I did find last night was a small portion of the spark plug cable shielding was rubbed away from hitting the cowl. I could see the insulation for the main wire underneath but no breaks in it.

Another thing was when I removed the engine today I notice that the metal ring the spark plug sits into (the one with the set screw) was loose and popped out easily.

I said those last two things to ask this question..... Has anyone change out the plug clip to a regular rubber boot? I don't like the idea of that small screw holding in such a vital part and now that I have found that ring loose I'd like to do away with it all together.

As far as the engine cutting out.... Is it possible the old gas may have damaged the internals of the carb? Could it be something with the new gas, going from a 30:1 to 35:1 mix?

Not gonna mess with this much more today but any advice would be greatly appreciated.

RE: Problems with Evolution 45GX (not gx2)
 

ignition...not gas.
The ignition with the metal cap and shield wire is all that prevents you from glitching into the ground.
Rubber boot ones will not provide the same protection if any.
If you had a bad ground thru the cap or shield its possible the ignition may be damaged or was never right in the first place

RE: Problems with Evolution 45GX (not gx2)
 

Panzlflyer,

Thanks. I guess it's just coincidental that it all happened at once. As I had said the engine ran flawlessly on the old gas.....when it finally started! :D So to you think the EI unit should be replaced? Is there any way to check it out? I got a good spark rotating it by hand (about 20 times).

RE: Problems with Evolution 45GX (not gx2)
 

Panzlflyer,

I have some photos here of the sparkplugs. I apologize for the blurriness but I think you will be able to see what I'm talking about.

The original Brisk plug is on the right. The Autolite plug with the tip cut off is on the left. See how much larger the center electrode is on the Autolite? Is it possible that it's finding a ground inside the metal cap?

RE: Problems with Evolution 45GX (not gx2)
 

I have had the same problem. Last run for my 45mvvs was about 2 months ago, after installed it to new airframe, it could not start. Check the ignition with screw driver inside the cap, it has very bright spark but when put in the spark plug, it seems to have very little spark. Change to new plug and the engine starts only for a while and at half throttle and above, below half throttle no response. What I did take out the carb and clean everything, change new diaphrm coz, take out the small spring and clean up thoroughly. After installed everything, start again and it works fine. Forgot to mention, my iginition wire also got slightly damage by hot muffler and I wrapped it with heat shrink tube.

RE: Problems with Evolution 45GX (not gx2)
 

Sorry for the delay,
Its possible that its making a bad contact.
What happened to the old plug? Can you put it back in?
I rarely have a plug go bad unless there is something else wrong.
If you spin it over make sure that the plug is grounded to the engine as it will tend to burn up the ignition.
Look inside at the spring in the cap and make sure its okay, I had one break off on my ZDZ and the new plug may have squished it.
I personally like to do one change at a time...makes for easier trouble shooting.
The concern with the braid is not that it wont run but that it MAY expose your reciever to more RF than it likes.
It is also the ground for the ignition.