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  #1  
Unread 12-30-20, 03:44 PM
Rick Erwin Rick Erwin is offline
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I agree with mshac in that your best clue to the vibration is the cool #2 cylinder. Figure out why there's no fire in that cylinder.

Your 150-rpm mag drop is right at the limit for my TSIO-360CB. Yours might be different... Perhaps once you solve the cool cylinder issue your mag drop issue will be better also.

As for the increased force to move the rear prop lever ... If you have prop-sync, that's most likely due to the rear prop lever moves the prop-sync controller which is on the rear-engine. On the front engine it's a direct linkage to the prop-governor ... as I understand it. I had the same question when I got my plane and that's what I was told.

Rick
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Last edited by Rick Erwin : 12-30-20 at 10:48 PM. Reason: Clarity
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  #2  
Unread 12-30-20, 05:42 PM
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mshac mshac is offline
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Another thought for you -

Use one of those cheap IR temp pistols to check the cylinders and exhaust pipes. You know the kind, they usually have a red laser pointer on them. Maybe $25, most likely less. We'll call it the Poor Man's Engine Analyzer!

You can take some live readings while the engine is running. More than any particular temp, you're looking for DIFFERENCES between the cylinders.

Measure cylinder #2 (the suspect) with both mags AND L/R ONLY! You want three sets of data. Knowing what happens on L/R mag only is very helpful in diagnosis.

Measure the exhaust temp about 1" below the cylinder head. Measure the spark plugs, measure the heads. You'll quickly notice any cylinder that's "out of whack", and you'll have a good basis for determining the cause.

EDIT: Here is one for under $25:
Etekcity Lasergrip 1080 Non-Contact Digital Laser Infrared Thermometer Temperature Gun -58℉~1022℉ (-50℃~550℃), Yellow and Black
by Amazon.com
Learn more: https://smile.amazon.com/dp/B00DMI63..._kmq7FbZP5ZR8C

Last edited by mshac : 12-30-20 at 05:50 PM.
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  #3  
Unread 12-30-20, 09:49 PM
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Learjetter Learjetter is offline
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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.
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  #4  
Unread 12-31-20, 01:39 AM
wslade2 wslade2 is offline
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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.
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  #5  
Unread 12-31-20, 12:08 PM
JAG JAG is offline
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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
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