75 optimax thoughts

[Mwink]

Hey guys I'm new here but been lurking for a while. I have the opportunity to purchase a 2007 75 horse optimax. Seller states outboard has low compression in one cylinder. I'm a mechanic by trade. I would be putting this on my 18' starcraft Mariner that currently has a wore out not running 1990 90 3 cylinder Merc. Thoughts?

 

[Mwink]

Seller is asking 1000

 

[flyingscott]

Rebuild what you got. Do you know why the opti blew a cylinder? Parts are crazy expensive and they are not a do it yourself motor. There are many better options out there maybe keep looking.

 

[Mwink]

I don't know why. All seller said was they were out last weekend and it started running rough. Brought it back and compression checked it. I'd like to upgrade, this boat will be used for late fall early winter lay out hunting on lake Erie and that is mostly it. Hard to justify spending a ton of money on an out board that will really only get used 2 months out of the year.

 

[Scott Danforth]

then buy a running used outboard from midwest states.

$1000 is a lot to spend on a motor that you dont know what took out the power head.

 

[flyingscott]

That is not like rebuilding a carbed motor. You pay 1000 for the motor another 2500 to rebuild it your into it probably $3500. You could rebuild the motor you have for around a $1000 if you do the work yourself. The compressor alone on an optimax is around $2000.

 

[havoc_squad]

That is not like rebuilding a carbed motor. You pay 1000 for the motor another 2500 to rebuild it your into it probably $3500. You could rebuild the motor you have for around a $1000 if you do the work yourself. The compressor alone on an optimax is around $2000.

Yikes, hearing the cost of that part alone gives the feeling like making a trip to the dealer, asking for the part pricing, then getting the equivalent of a robbery at gunpoint demanding money. After the money is taken hastily, a crappy box with a part is slid over the counter.

I could almost pay for a remanufactured OMC V4 crossflow powerhead with warranty for what that stupid thing costs.

I'm sure all of the newer outboards are stupid expensive on parts, though I'm curious on which year(s) & model of the newer stuff is best for rebuild and maintenance.

Might have to search for a thread that discusses that, if it doesn't exist I'll probably create one in the non-repair section.

 

[Chris1956]

Optimax is a direct injection 2 cycle motor. The pistons/cylinders themselves are pretty standard, and could be rebuilt in a standard fashion. However, that motor uses high pressure fuel pumps and an air compressor to force fuel into the combustion chamber at near TDC. It therefore has all the complicated electronics of a modern automobile engine, plus some specialty systems. It is also run in high humidity conditions which is hard on the electronics. You also do not know why the cylinder failed. It could be the gasoline injection system, the compressed air system, the oil injections system or something else like overheat.

For your short season, I would recommend something simpler, like a carb 2 cycle motor.