Al Marzo wrote in
:

No matter who tries to be gallant and come to their rescue, they'll be
10+ others who have experienced the crap that TCM put out called
"cylinders". 700 hours is about all you can expect from a TCM
factory cylinder before taking it off and sending it out to be done
properly.

To be fair, not ALL of them break in with this problem... but a large
number do.

Heck, I even know a few people who have taken the cylinders
off of a new TCM engine so that they may be corrected before putting
them into the plane.

True... LPM (a magazine widely respected in the field) insists no
reputable shop would put a new TCM cylinder onto an engine without at
least first mic'ing everything and almost always having to relap the
valves.

Sad story especially since they seem to spend
more on marketing than they do on quality assurance and control.

Also sad, since one of the things that started this whole sad (and
expensive) story years ago was an attempt by TCM to actually IMPROVE
their engines. Now their latest approach (almost certainly to stave off
a class action suit) is just to continually lower the limits on an
"airworthy" cylinder. It's now so low (26/80 with air leaking past the
rings and valves, and a pressurized crankcase) that pretty much any
piece of scrap iron is considered "good" by TCM.