Spark Plug Question

bob888 · #1 02-10-2021, 08:56 AM

I have been using the recommended UREM37HE plug with my electroair ignition and also a UREM 37BY with the magneto on the other side. Both these plugs have the projected "BY" style electrode. I recently noticed that the Lycoming SB1042AC shows that the BY plugs are not listed as approved for any of the 540 series engines. My engine seems to be doing fine with these plugs, now over 450 hr. Are others running "BY" plugs? Any problems?

Bill.Peyton · #2 02-10-2021, 02:35 PM

Bob,
I also have the electro air ignition. I was running the urem37he in the top with the EI and REM38E with the mag in the bottom. I had 500 hours with this setup. Recently I switched the lower plugs to the fine wire REM38S and noticed a dramatic improvement in the mag and with single mag operation. So I decided to also switch over to the same plug with the Electroair, an REM38S. I had to re gap the plug to .032 using the tempest fine wire gapping tool. I did not notice any difference in the performance of the EI. Electroair does not sell a REM version of the fine wire, just the RHM 3/4 dia longer plug, which will not fit under the RV10 cowl.
Bill