Rough Engine

[Friesen5]

My Sonex with a Jab 2200 has been flying since 2007 and has 480 hours. I just completed my annual this spring and was preparing for a test flight. The engine started but was running quite rough. Further testing revealed that cylinder #1 was the likely problem. I conferred with several friends and came to the conclusion that it was likely a valve problem. I started by removing the valve covers. I discovered the valve adjuster laying in the cavity.

I replaced it, adjusted it to .010" and put the valve covers back on. Now when I started it, it ran smoothly. I put the cowls back on and went for a test flight. The engine was smooth and ran well.

How did the adjuster get so loose that it actually came out of the rocker? I don't know the exact answer, but probably I didn't tighten it sufficiently when I did the annual in March.

I'll be mindful of that every time I check the valves in the future.

Mervin Friesen

[Skippydiesel]

"To err is human, to forgive divine" - we all make mistakes, don't beat yourself up too much.

Thank you for your courage in reporting your incident - it is stories like this, that keeps all of us alert to our own potential to make a simple, possibly catastrophic, mistake.

[pappas]

What a lucky guy you are! My Aerovee Turbo snapped the valve adjuster while at 3500 ft over the desert. You need to buy a lottery ticket, pronto!