SureFly and Plug Fouling

[Whiskey25]

Looking for any help to solve our issue. For background, currently have AEIO 540 that was running standard mags and aviation plugs. The engine was built by Barret's adn has higher compression 11.5-12.0:1 and we were having a lot of issues with hot starts. We made the decision to swap the left mag with a SureFly unit a few months ago and we have noticed more fouling of plugs and running rough. The only plugs fouling are on the SureFly system and the other plugs have been fine. We thought perhaps we weren't getting the best performance from the standard plugs and switched to auto plugs thinking it would give a better more consistent spark; unfortunately this hasn't improved our situation. We have changed to better quality iridium plugs, checked all the leads, tried both variable timing and fixed timing. We sent the SureFly unit back to the manufacture and was bench tested ok.

This is extremely frustrating as we can't seem to find a root cause other than all the fouled plugs are on the SureFly. We are considering going back to a Slick mag and abandoning the SureFly. Has anyone else had similar experiences? Any recommendations?
Cheers
W

 

[MiserBird]

What type of plug wires on the SureFly? Plug gaps?

 

[steveandmaysrocket]

Looking for any help to solve our issue. For background, currently have AEIO 540 that was running standard mags and aviation plugs. The engine was built by Barret's adn has higher compression 11.5-12.0:1 and we were having a lot of issues with hot starts. We made the decision to swap the left mag with a SureFly unit a few months ago and we have noticed more fouling of plugs and running rough. The only plugs fouling are on the SureFly system and the other plugs have been fine. We thought perhaps we weren't getting the best performance from the standard plugs and switched to auto plugs thinking it would give a better more consistent spark; unfortunately this hasn't improved our situation. We have changed to better quality iridium plugs, checked all the leads, tried both variable timing and fixed timing. We sent the SureFly unit back to the manufacture and was bench tested ok.

This is extremely frustrating as we can't seem to find a root cause other than all the fouled plugs are on the SureFly. We are considering going back to a Slick mag and abandoning the SureFly. Has anyone else had similar experiences? Any recommendations?
Cheers
W

I've been running Surefly on two different airplanes one four cylinder and one six, for four years. I had fouling initially with massive electrode (standard) spark plugs in my 520 and switched to fine wire plugs and have never had another issue, regardless of elevation, temp, nothing....I prefer the fine wire plugs anyway. I run my Surefly on my top set of plugs and Bendix on my Bottom set.

I can't tell the difference whenever I check them for coloration or deposits, but will say when I run at extremely low power settings, like...1900 rpm/ 17"mp The Surefly is so smooth that I occasionally shut my bendix mag off, as it roughens the purr...which I assume is due to the advance feature of the Surefly.

Hope that helps!!


Steve.