2003 Optimax 200hp DFI Seized Piston Repair Options

I recently picked up a 2003 Triton TR19 with a 200hp DFI (serial 0t665139). It was seized so I got it for essentially nothing. I finally got it apart and it looks like cylinder six leaned out. I was hoping I would get lucky and would be able to clean up the cylinder with acid and hone it. Unfortunately, the rod knocked out some of the cylinder sleeve.

I'm looking for input on whether or not re-sleeving the cylinder is a logical or even feasible option. There's some pretty bad damage on the head at the bottom of the cylinder.

Would going with a remanufactured powerhead be a better option? As I said, there's very little invested in the boat at this point and will sell my Nitro when this is ready for the water.

I will be getting the fuel rails cleaned, injectors serviced, and check the air compressor regardless of which option I go with. Anything else I should get serviced? Probably worth noting that it's got a brand new lower unit and the hull itself is in great condition.

Attachment 479057Attachment 479058

I own the same motor so this is an ez question. Part that motor out as pure profit and put that $ towards a running motor.

Probably not a "lean out" condition... very likely a COLD SEIZURE (failure of that cylinder to reach operating temps before "hammer down"). Note the orientation of the worst damage directly over the exhaust port.

OEM/Mercury remans for this are no longer available. Given the engine's age- you would come out further ahead parting it out (and getting into something newer).

Pulled ring also, cold seize this time of year

I actually have some friends that wont even run their engines when it gets below freezing, or let it idle for 30 minutes

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Originally Posted by Another Distraction

This opti 0.0055" piston clearance issue must have been addressed and fixed at one point. Do all opti's have this issue?

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Never seen one with that issue, from the factory. Of course- you can accomplish it due to operator error or thermostat malfunction in a matter of less than 30 seconds, since the piston expands at about 40 times the rate the sleeve does (just fire it up, slap it in gear and hammer down- eventually it's going to cold-seize).

nor have i , guys you got to have a way of monitoring engine temp in this cold of water, needs to be mandatory , i rarely see it after temps rise above 60 dgr , not saying it wont with a stuck open stat esp on port side

Quote:

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Originally Posted by Another Distraction

I got the 0.0055" issue lesson from the cold water FAQ. Sounds like Merc didn't do a tolerance evaluation on their parts. Luckily my 1,700 hour opti is all worn out so I have a lot more than 0.0055" now!

http://www.bbcboards.net/showthread.php?t=25829

"The expanded piston don't have the .0055 clearance needed and it will seize or stick to the cylinder wall"

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5.5 thousands clearance is what that is discussing. Problem has nothing to do with the factory tolerances, and everything to do with cold water, cold engines, and the differences in expansion rates of metals. Gonna purge this thread of this material as it's not really related to the original topic.

Sounds good, sorry.

The previous owner said it was on the last run of the day back to the ramp and it occurred in late October or early November (mid 50s water temp) so I suspected lean out more than cold seize but I trust your judgement. Thinking about it now, he did say it was at WOT when symptoms occurred.

If I were to find a remanufactured powerhead with a warranty what are your thoughts about going that route vs. parting out and repowering?