When is it time to get an overhaul?

[KSMooniac]

FWIW, when debating what to do with mid-time cylinders when there is a low compression or bad valve issue, don't automatically opt for overhauled cylinders or new cylinders.  If you remove a cylinder, have it inspected by a good shop and just replace what is necessary.  Far cheaper, and if you have known, good parts that still meet inspection requirements, then there is no need to replace them!  As soon as you install new parts they'll be used parts just like the ones you replaced.

[MB65E]

Plus with overhauling your cylinders vs exchange, you know what heat cycles were on them. The exchanged cylinders are a crap shoot.

Unless you know your cylinders are shot, have high time, or cycles, I'd lean towards working on what you have.

-Matt

[rainman]

Cylinders 3 and 4 are the offenders. Boroscope shows cracking (looks like surface cracks not straight scrapes) on both cylinders. No metal in the oil analysis. Cylinders are off to machine shop to see if they can be reconditioned or need to be replaced. More to follow next week. Ray

[rainman]

Here is a photo, both look the same. Not good. Ray

[carusoam]

Are they by chance, chromed?

Or other surface treatment on the internal surface?

Nice photo evidence of what is going on!

Best regards,

-a-

[rainman]

Not chromed. The engine was factory new in 2000, and had 400 hrs when I bought the plane three years ago.

[ryoder]

How much does it cost to get a borescope?

[aaronk25]

Hour of labor......or free if you come to RST as I could take a peak I have the latest snap on borescope

[KSMooniac]

Well, that sucks!  Sorry to hear this...you might check the other 4 jugs and maybe talk to CMI since they made these.  They might give you a discount on new jugs even out of warranty.