I Finally Figured It Out

That's what my dad always used to say, "I finally figured it out". He was always talking about the meaning of life. In my case, I just want to figure out how to make the damn engine run.

Thanks to Lynn French, I definitely know the ignition problem is due to my trigger wheel and sensor assembly. Lynn was kind enough to lend me his parts, while his engine is down, and I bolted it on this afternoon. Lynn has the 7" trigger wheel, while I have the 6". I used my existing sensor and wiring.

The engine fired up just fine, as always. After it warmed up I ran it all the way to 2,320 RPM. I haven't seen the engine turn that fast and smooth in a year and a half. While I was at WOT I switched off the mag and the engine didn't miss a beat.

Here are some photos of Lynn's trigger assembly mounted on my plane. Compare them with my installation in my previous post, dated April 19.


So, without a doubt, the smaller wheel must be causing me to pick up noise from the crank flange and prop bolts.

That's the good news.

Now, I have to figure out what to do about it. My first inclination is to see if I can find a different sensor and use the existing wheel. I have a lot of $$$ in that trigger wheel, and looking at Lynn's parts, I'm sure he even has far more machining than mine. I know a rep for an industrial sensor company and I'll give him a call tomorrow.

Maybe I could use an aluminum plate, with the embedded magnets, like Klaus uses. I would have to know if that type of Hall Effect device would work with the EC3.



Any other ideas?

Figuring out the Electronic Ignition

Gee, no posts for a month. You'd think I wasn't doing anything. Actually, I've been stymied by the engine. The general symptom has been that I can't get full RPM. Before I started this conversion, I was getting 2,300 static RPM - now I can only get around 2,100, and it's rough.

Yesterday, I finally narrowed it down. The problem is definitely with my electronic ignition, and most likely my installation portion of it.

Yesterday, I ran the engine again, but this time I hooked up an automotive timing light to the #1 spark plug lead and kept the light in the cockpit to closely watch the flash and see what it was telling me. At low RPMs, idle through about 1,500, the flashes were nice and steady - just like when I did the Mode 8 check with the engine off.

However, as I started to raise the throttle, the flashes became intermittent.? It's as plain as day and I don't' know why it took me this long to see it. The faster the engine ran, the worse it got.

When I retarded the throttle, as I came back down to the 1,500 range the flashes on the timing light became nice and smooth again. So, now all I have to figure out, is why this is happening.

I still think there may be trouble in my 6" trigger wheel/sensor installation - possibly picking up noise from the crankshaft flange and prop bolt lugs. Lynn French's engine is down right now and he is kindly lending me his 7" trigger wheel and mount, and they should be here soon. Swapping those parts should quickly confirm or disprove that installation issue.