handfulz28

Say on the rectangle port manifolds...are there any signs of the common cracking that can be seen with the naked eye? Do you have to remove the head in order to see?
What about popping the freeze plugs? Just how much can you inspect through there? I assume pulling the block drain plugs might also give an indication, based on what comes out...or not. and that's assuming you can actually get 'em out easily enough.

What else can/should be inspected visually, with no/minimal disassembly, before determining that the motor is junk? As a seller, where would you draw the line for part removal? As a buyer, how far would you push to inspect before deciding whether or not to buy?

If it's worth anything to the decision process, the engine isn't a fully dressed "ready to drop in" but say a complete core for rebuild so there would be some expection of labor/machining. But as is typical, advertised as "running when removed".

problemchild292

michael, i bought my formula this year 6000 below market. i now know why. one bad motor after 1 weekend. another bad motor 2 runs after i built the first. still in pieces. i bought a core 454 with oval port heads, had my work done, and topped it with edelbrock rpm marine heads. core truck motors go for around $650. back on subject, priority 1 for me from now on is a compression check. it's the easiest way to check the cylinder wall, valvetrain at one shot. i know on a 2 stroke the allowance is around a 5 psi variance between holes on a used engine. i would maybe pull a valve cover and check for cleanliness and water. pull the oil pan plug too. if it's bad, chances are you'll need to replace the crank due to wear. machining marine cranks isn't recommended. hope this helps, Eric

Quaid24

I would take it a step further and perform a leak-down test. Unlike a compression test, this can be done without putting power to the motor and having the starter rotate it and it is a much better way to see if the motor is any good. It will let you know how well the entire combustion chamber is sealing. The rings, valves, head gaskets, etc.

If you only perform a compression check, from what I am told, up to a 10% varience is acceptable. A typical boat motor should be around the 140psi-160psi mark. I dont build motors for a living so be sure to do some more research. I could be off on my numbers.

Pulling drain plugs and freeze-out plugs will most likely be a waste of time. Anyone should be okay with you pulling the valve covers and oil pan. If they refuse, walk!