I have a 93 skeeter bass boat with a 200 mercury that just recently siezed up.  I have the option to buy a 97 225 Merc. that was used in saltwater.  1. is it ok to buy a saltwater if I am going to use in freshwater.  2. What types of problems typically occur with saltwater motors.  What would the typical compression be on those motors.  It is listed on ebay so I cant see it.  Any information would be great.

Thanks,

Jenga

Dude stay away from salt water pm me what you want to spend and ill help you get hooked up with a good motor that will last

If you know a good wrench turner, a rebuild would be your least expensive way to go.  A friend of mine just had a 200 EFI bored .015 and it is running like a charm.

His total outlay was $3000.

That old of a saltwater motor, you are asking for some very expensive problems.

First, it's a good chance you will have cooling problems, even though it runs fine.

When it comes time to do any kind of repairs, the corrosion is going to cause screw, nuts/bolts not to come out, break off and very time consunsuming to get them out.  Sometimes it requires a new part because at $100 per hour, it's cheaper.

Matter of fact, it's a good chance you can't even get the lower unit off to change the water pump.  It's very common for the drive shaft to be rusted into the crankshaft if they didn't do regular changes on the water pump. 

I could go on and on but basically, I wouldn't touch if with a 10ft pole.

I can't rebuild the power head in my 200 merc. due to the fact that the block is cracked.  If the 97 225 merc. is corroded couldnt I take the power head from that and put it into my other motor.

Thanks,

Jenga

Your best bet would be to go here http://forums.screamandfly.com/forums/forumdisplay.php?f=20 There on guys on there that can tell you anything you need to know about mercs. I'm not a black motor man.

I'm not sure if a 97 powerhead will fit on a 93 LU or not. Even if it will, you still have the same problem with corroded bolts. If the drive shaft is stuck in the crank like they are subject to do, you may not get the powerhead off. I would pick the guys on S&F's brains.  The other problem is the water passages in salt water motors get blocked, that's why I mentioned cooling problems.