buying a 150 optimax, questions

[rsw21282]

Hey guys im getting ready to buy a new boat. 2005 21 cc seafox with a 05 mercury optimax 150 w/300hrs. My question is what things should I look for? Im gonna check compression, lower unit oil, and condition, what else? also does anyone know what the optimal compression for that motor is? anyone know the rpm at wot of the eng when properly pitched prop? anything these motors or boats are prone to?

compression checking, do most of you take all plugs out then check or run one at a time? disconnect all plug wires or can that hurt the coil?

 

[sutor623]

Re: buying a 150 optimax, questions

Check the articles in the FAQ page. JB (I think) did an excellent explanation of how to do a compression check. And most of us on here would say that if you cant take the boat for a test drive, then you are playing with the odds. I have had motors run great on muffs in the driveway, and when it came time to go for a ride it was a different story. Plus you cant tell if there is a spun prop hub in the driveway. Just my .02.

 

[1nebel0]

Re: buying a 150 optimax, questions

Opti's can be costly to operate...you have an air injector as well as fuel injector for each cylinder...While they are extremely popular, they do cost a lot to maintain. Come out of the water and over-rev them say goodbye to a couple of cylinders due to broken metal reeds taking out the cylinder.. The pro XS has Fiber Reeds...Hmmmm wonder why they all don't given their history of breaking them.. I bought an 2006 for $1500 that looks brand new from a pro... he came out of the water and didn't throttle back and the rest is as they say history. He went out the next day and bought an $18,000 Pro XS.....now I have to sleeve two cylinders and new heads, new pistons etc etc....maybe that is why it is in storage for the past 4 years.....good luck...talk to your local shop....

 

[rsw21282]

Re: buying a 150 optimax, questions

what symptoms does a motor that has had that happen present? obviously getting the reeds replaced is neccessary but will an engine run with scored cylinders, or what signs will it show? low compression?

 

[sutor623]

Re: buying a 150 optimax, questions

what symptoms does a motor that has had that happen present? obviously getting the reeds replaced is neccessary but will an engine run with scored cylinders, or what signs will it show? low compression?

An engine with blown reeds will be hard starting/running if it even starts at all (doubtful). An engine may run with scored cylinders, so a compression check is necessary. Look for any peeling paint on the head of the motor. That will sometimes identify a motor that has run hot. Check out the FAQs on here I think they have one that tells you what to look for when buying a boat/outbaord.