Rough O200A

[paulk]

Hi All,

When I purchased my used (~300hr) Sport Cub, the engine would occasionally run a bit rough. Playing with the mixture or carb heat would sometimes smooth things out a bit, but it just never ran “right”. You probably know what I mean, you cant put your finger on it exactly, you just sense all is not well. I had flown a few dozen hours behind other O200s (some better than others) so I had a general sense of what normal was for these engines.

I decided to install an engine monitor, mostly to keep track of CHTs but installed the EGT probes to help diagnose the roughness problem. I hate throwing parts at a problem in hopes that the problem just goes away. Anyway, after downloading the engine data from a few flights it was evident that the intake hydraulic lifter on one cylinder was misbehaving. After replacement the engine is now super smooth, well as good as any other O200 I have flown behind I now have around 15 hours after the fix now, so I’m confident that the problem is solved.

Hopefully this information might be of help to others. If anyone has a question please drop me a message.

Paul K.

[Pete D]

Thanks for the tip!

[txcub]

What type engine monitor did you install and where did you put it?
Jon

Hi All,

When I purchased my used (~300hr) Sport Cub, the engine would occasionally run a bit rough. Playing with the mixture or carb heat would sometimes smooth things out a bit, but it just never ran “right”. You probably know what I mean, you cant put your finger on it exactly, you just sense all is not well. I had flown a few dozen hours behind other O200s (some better than others) so I had a general sense of what normal was for these engines.

I decided to install an engine monitor, mostly to keep track of CHTs but installed the EGT probes to help diagnose the roughness problem. I hate throwing parts at a problem in hopes that the problem just goes away. Anyway, after downloading the engine data from a few flights it was evident that the intake hydraulic lifter on one cylinder was misbehaving. After replacement the engine is now super smooth, well as good as any other O200 I have flown behind I now have around 15 hours after the fix now, so I’m confident that the problem is solved.

Hopefully this information might be of help to others. If anyone has a question please drop me a message.

Paul K.

[paulk]

It's a JPI 730, which fits in a standard instrument hole. Mine is just to the right of the avionics stack in the lower factory hole.

Paul