Re: Best years for OMC 10 horse?

[Don]

quote FrankR:

In my not-so-humble opinion, eliminating the powerhead pulling requirement was the worst thing they ever did to that series. Sure it made it easy, but it also eliminated the requirement to at least look at the crankshaft carbon seal. One of the biggest causes of thrown rods, even though most people blame it on the oil.

You are so right Frank. The later models, with the cup in the exhaust housing actually made matters worse. Trying to pull that gearcase down slightly, removing the coupler screw, and aligning the driveshaft pin with the slot in the housing, is near impossible. I have rarely gotten a gearcase down without shearing the roll pin off. I’m sure many 6hps have gone back together with the sheared roll pin, not to mention cobbled up shift rod coupler screw. I am ashamed to admit, that as a young technician, I know I probably overlooked a few myself.
Removing the powerhead on these engines only takes a few minutes, provided the powerhead screws have been out before and lubed up on reassembly. Here is a rare case where OMC spent more money in an effort to make things easier to work on, but created more long term problems.
This lower seal assembly is not understood by most technicians that deal with it, heck, I still don’t fully understand how those crazy pieces could work correctly.