Engine Miss 2100-2500rpm

Here are some thoughts:

When you get the misfire, is it still worse on one ignition or is it similar on both? If you immediately stop the engine when it is misfiring, what does the fuel level look like in each float bowl? Are the small drillings in the venturi near the butterfly clear and unblocked?

Is it an actual engine miss or a vibration? The reason I ask is to help rule out the gearbox. With 1190 hours when was it overhauled?

Kevin,

It's the same on either ignition. I've checked all the ports and passageways multiple times.

Same thing with the floats! They are good as well as the level. Having had 20 floats sink on me over the years, I've gotten good at this task.

Thanks Kevin!

Roger,

It's an actual engine miss. You can hear it and see the engine shaking.

The gearbox was rebuilt at 650 hours by Ronnie Smith at South Mississippi Light Aircraft.

Thanks Roger!

Having had a number of faulty ignition modules over the years I've disassembled some to look at the circuitry and I haven't seen an issue with them that would cause a misfire over a particular rev band.

I did have a failed inlet valve where the sealing face was worn/deformed. That started off as a misfire that rapidly got worse to the point where I was scared to fly. It was only diagnosed when the engine was stripped down and rebuilt but that was when my oil consumption problems began. In the end I just purchased another second-hand engine as it was all taking too long to diagnose and repair.