1993 Mercury Black Max 200hp - worth the repair?

[ajharry]

I have an old 1993 Mercury Black Max 200hp that the boat shop has just told me is giving 80 psi compression in one of the cylinders (the other 5 are still around 120). It looks like it was caused by the carburator being a bit clogged up causing the cylinder to run a bit lean potentially resulting in some scoring on the piston or cylinder.
The estimated repair bill will be up to NZ$3000 to pull it all apart and fix it up. It's quite a bit of money which I'm not sure if it's worth investing into the old engine where problems are popping up quite often. The alternative is to run the engine until it dies and put the money towards a new engine (roughly NZ$14000), as according to the repair shop, the engine seems to be running pretty well (no vibrating or obvious loss of power) it's just the low compression. We only use it up to 40 hours a year for water skiing, so hoping maybe it will last a couple years before it gives up completely. But to be honest I'm quite clueless when it comes to boat motors.
What do you guys think? Should I pay to get the engine repaired, or would it be throwing good money after bad?

 

[Alumarine]

Welcome.
Could you not just run it the way it is?
Does it currently put out enough power for you?

 

[ajharry]

Thanks for the reply. We can, but would the lower compression from one of the cylinders now create uneven balance on the crank shaft and cause it to wear out pretty fast?

 

[bajaunderground]

I had my 200 Mercury rebuilt for $3,200USD and ran for 7 years @ ~50hrs/yr?!

 

[sam am I]

Perhaps just going after the one bad hole would be less? Hard to only do one hole once you're in knee deep but, if the others are in pretty good shape still, its do'able. With maybe a few seals here and there and for maybe half again as much, IDK......Few others here might chime in and can pin down the cost just going after one or two holes. I'll take the motor off yer hands if ya don't want it

 

[Faztbullet]

I wouldn't try to run it as its already damaged and could sieze causing more expensive damage like

 

[achris]

...We only use it up to 40 hours a year for water skiing,...

There's your killer right there. Water skiing puts more load and strain on an engine than any other activity. Hard 'idle to full throttle' starts, constant changing of load as the skier 'weaves', sudden stops.... Can't think of a worse scenario.

Just one low lung, get it fixed. Before it's the whole engine. If it has 'nipped a piston', just that piston can be changed and the cylinder bored out to the next oversize. The piston makers make sure the pistons are weighted the same regardless of oversize.... The beauty of an outboard.... Let's see those inboard boats do that trick.

Chris.......

 

[ondarvr]

I always look at it as a full rebuild, or get rid of it.

It takes the same amount of work to replace 1 piston and rings as it does all six, and the other 5 piston and ring combo's are the only additional cost, you still need to buy and replace everything else involved.

 

[achris]

I always look at it as a full rebuild, or get rid of it.

It takes the same amount of work to replace 1 piston and rings as it does all six, and the other 5 piston and ring combo's are the only additional cost, you still need to buy and replace everything else involved.

In this part of the world, internal outboard parts cost an arm and a leg....