Excessive vibration

[Learjetter]

Thanks guys! I’ll do as suggested.

Mshac— the airplane came to me this way, which is why my priority 1 is an EDM-960 or similar.

[wslade2]

Ditto. Mine came without engine monitor.

I’m in the process of installing engine monitor. Reason: had some cylinder work, mag work and Fuel system work done. On run up engine very shaky. We kept going over and over everything we did and couldn’t find a fault....until I leaned over and burned one hand while the other rested comfortably on neighboring cylinder. Problem was cold cylinder. Long story short. There was the smallest amount of grit plugging injector. Definitely work on your cold spark plug problem. I could have saved a couple weeks if I had installed engine monitor from getgo.

Also, 1 inch of movement seems like a lot. Look carefully to see if you engine is sagging. Motor mounts (rubber cushions) may be shot. I know cause just had that problem too.

Couple years back, had similar problem with my new to me 182 at take off. Wasn’t terrible but could feel it. It was everything together: bad mounts, 1 weak mag, high resistance plug, one cylinder had induction leak (caught those last three via engine monitor) and topped it off with dynamic balance. Wah-la! Problem solved.

[JAG]

Everyone has added great advice on digging further into #2 cylinder - so I won't dogpile on there.

Just a couple more thoughts on rough running/vibration. If your engine ignition, timing and mixture is all correct, you should not have any vibration. I can idle my rear engine at 675 RPM, and there is no vibration or beer spilling. Getting the engine set up right on the above items is important. A good A&P should be able to sort it quickly by starting with the simple things first; magneto timing, spark plug lead testing, spark plug testing (I would just replace with new ones...), cleaning and testing the injectors, checking for induction leaks, then performing the proper checks on the fuel system (SID97-3G).
Jeff