[June 3, 2011]

Today's weather was absolutely great. Low winds on the ground and at altitude and unlimited visibility. Not a cloud in the sky. I thought I'd take a quick flight over to KCBE (Cumberland, MD) just for fun. 34 minutes at RV speeds. It is probably at least a 2.5 hour car drive.

When I started up the engine, it ran perfectly. One thing I did notice was the CHT for #3 was climbing much faster than any other CHT. I didn't pay much attention to that since it is the cylinder that has the least amount of airflow over it.

Once I climbed up to 6,500' to find some cool air, I leaned the engine back. With the power set to 65%, I usually am able to lean it back to 7.5 GPH before the engine starts to hesitate. Not today. At around 9.5 GPH the engine started running very rough. I also noticed the EGT for cylinder #3 drop. Also, the CHT was pretty low for #3.

When I saw this, I stopped heading for KCBE and went right back to Westminster. I didn't know what was going on, but it was something I wanted to figure out.

Pic of the south side of Frederick, MD. Like I said, perfect day.

Once I landed in KDMW (A nice bouncy landing to boot), I yanked the cowl and plenum off to do an inspection. Everything seemed fine. I yanked out the top plug and it looked fantastic.

I also yanked out the injector. I cleaned this up (although it was pretty much spotless) and reinstalled. I started up the engine and it still ran a little funny. High EGT's on #3. I leaned it out and it started running a lot better. However, I could never get any conclusive run-up tests. I think the bottom plug is fouled up now. I am going to try to take them out tomorrow morning and give them a good cleaning.



Last Modified: May 19, 2024