SureFly with EAREM37HE plugs? Slick failure?

[John Mininger]

On my way out to Oshkosh this year from eastern Pennsylvania, my engine started running a little rough. I initially thought it might be my leaning technique, but the slight roughness persisted. I finally did an inflight mag check and found that my left mag was dead. Long story short, I landed at AGC, rented a car, drove to Oshkosh, and had the Slick 4372 replaced with a SureFly which I bought from Spruce at Airventure and had overnighted to the A&P at AGC. The engine is a IO360-A3B6. In the interest of simplifying the away from home installation, I did not have the manifold pressure line installed. The timing is fixed at 20 degrees BTDC. So far, so good, but my CHTs are running higher even with the fixed timing. I can't get close to POH 75% power numbers without the CHTs going over 400 degrees. I have to be either way rich, or way lean. I'll play around with that in the coming colder months. 

Two questions:

My Slick 4372 only had about 400 hours on it since new. I bought the factory rebuilt IO360 A3B6 with the new mags in late 2019. Has anyone else experienced premature Slick failures? I talked to two other guys just on my airport alone that have. One guy had two failures! Both with lower time mags than what mine were!

And my other question is: Is anyone using Tempest EAREM37HE plugs with their SureFly SIMs? Those plugs were originally developed for Electroair, but SureFly will tell you that they're OK to use if "your engine is approved for them".

Frustrating stuff. I was planning to replace the Slick 4372 at 500 hours anyway. But not at the beginning of a trip, away from the home field at 400 hours.

Thanks, John

[Shadrach]

52 minutes ago, John Mininger said:

On my way out to Oshkosh this year from eastern Pennsylvania, my engine started running a little rough. I initially thought it might be my leaning technique, but the slight roughness persisted. I finally did an inflight mag check and found that my left mag was dead. Long story short, I landed at AGC, rented a car, drove to Oshkosh, and had the Slick 4372 replaced with a SureFly which I bought from Spruce at Airventure and had overnighted to the A&P at AGC. The engine is a IO360-A3B6. In the interest of simplifying the away from home installation, I did not have the manifold pressure line installed. The timing is fixed at 20 degrees BTDC. So far, so good, but my CHTs are running higher even with the fixed timing. I can't get close to POH 75% power numbers without the CHTs going over 400 degrees. I have to be either way rich, or way lean. I'll play around with that in the coming colder months. 

Two questions:

My Slick 4372 only had about 400 hours on it since new. I bought the factory rebuilt IO360 A3B6 with the new mags in late 2019. Has anyone else experienced premature Slick failures? I talked to two other guys just on my airport alone that have. One guy had two failures! Both with lower time mags than what mine were!

And my other question is: Is anyone using Tempest EAREM37HE plugs with their SureFly SIMs? Those plugs were originally developed for Electroair, but SureFly will tell you that they're OK to use if "your engine is approved for them".

Frustrating stuff. I was planning to replace the Slick 4372 at 500 hours anyway. But not at the beginning of a trip, away from the home field at 400 hours.

Thanks, John

Has anyone verified the timing by observing spark at the lead?  The Lycoming IO360 was certified at 25° of advance.  20° of advance was added to the TCDS at a later date. Many of us are running 25° with cool CHTs.  I can envision no scenario where 20° of advance would produce the symptoms you're experiencing. It seems unlikely that the increased spark energy of the Surefly would increase flame front propagation sufficiently to cause an increase CHT, ergo I would ensure it is properly timed.

As for the Slick failure.  Any magneto can fail. The question is what component failed. There are a number of component failures that would cause the scenario you describe.  If you ever again find yourself operating in on a single mag in flight, it is perfectly fine to adjust the mixture to increase the speed of combustion (flame front propagation).  This would entail leaning the mixture if ROP or enrichening the mixture if LOP. This will help to recapture lost power and reduce any roughness until the flight is completed.  Note that losing a mag while running LOP is more likely to result in noticeable power loss and roughness.

While it is getting harder to find A&Ps that will open a mag, there are still many that are willing.   

For future reference, a repair kit is available for the Slick 4370 through airpower for $175.00. Kit includes the following:

• Contact Point Kits
• Double Sealed Bearing
• Bearing Cap Assembly
• Condenser
• Rotor Gear
• Cotter Pin
• Coil
• Distributer Block and Gear
• Woodruff Key
• Oil Seal
• Washer
• Impulse Coupler

[PT20J]

First thing I would do is verify the timing. My Slicks that came with my rebuilt in 2018 have been fine. Coming up on 500 hrs.