Vidic,

I was wondering about you the other day….

Just an opinion, but you have something else going on. I have no idea what it might be, but….

How did we get from 165psi on all cylinders to 120-130 on five of them? Were the rings intact? What did the pistons look like? Were the lands between the rings still intact? How are the cylinder walls? Something had to be bleeding off cylinder pressure.

While you’ve got it torn down, and I know this prospect sucks, but replace the Achilles heel components. Call Merc tech support, have them run your serial numbers and confirm whether you have a forged crank and rods or not. If not, replace them with forged. Either way, you will still have those damned hypereutectic cast pistons, so replace them with forged. If I’m spending your money, I’d go with Molnar crank and rods and JE pistons. You will have a virtually bulletproof engine at that point. Not that this will inherently solve whatever you have going on that took your compression out in the first place. Gotta get that rooted out first.

As bad as this sounds, here’s to hoping it was just a bad rebuild and the compression got wrecked on first start. Is it at the same shop that did the first rebuild?

B ring
O n
A other
T housand

Welcome to the club. Keep your checkbook at the ready. 😖

Thanks. Brad.

how many hours on engine?

forged crank and rods, just post photos of each?

Thank you all for helping me out! In the end everything is good the engine is running smooth first 10 hours are already done. I am right now on the water :)
what was done to the engine in this year:
- new exhaust,
- new water pump,
- new pistons,
- new bearings,
- new spark plugs,
- new gaskets,
- new termostat and housing,
- rebuild cardan,
- new transom,
- new starter,
- completely rebuild heads with ventils and everything,
- new bealt,
- block rebuild,
- circulation pump,
-… 😂
https://cimg8.ibsrv.net/gimg/www.off...239c53009.jpeg

it is 595 hours on the clock but probably previous owner overheated the engine..