1997 Mercury 40hp 4 cyl. Low Compression

[JMailbox8]

Hello,

I was looking for an engine to power my boat and found a 1997 Mercury 40hp 4cyl. C40ELPTO that a guy was selling in the classifieds. It runs and is in beautiful cosmetic condition, but has low compression. He is selling it for $600. Is this a good price, or would I be going in way over my head for the repair? I would be doing the work myself. He said it ran fine before the incident, and doesn't really know what happened. Should I walk from this? Thanks in advance!

 

[55evinrude]

Re: 1997 Mercury 40hp 4 cyl. Low Compression

well first off if you haven't gone to look at it in person do so, without doing test yourself you cannot decide if its worth it. I would also find out what this "incident" was that all the sudden made it run bad and have low compression....maybe a lack of lubrication or broken rings. a leak down test may even help determine where your loosing compression, and also check and see if its all cylinders with low compression or just 1. your best bet is to try to get it for parts value that way if its not worth it you can part it out!

Nathan

 

[sutor623]

Re: 1997 Mercury 40hp 4 cyl. Low Compression

Since you are new to boats (or at least this site) just pass on this huge project. The answer is yes this is over your head unless you want to pay for a full rebuild. 4cyl rebuilt would cost you around 2grand in my neck of the woods. Just a rebuilf kit for a do it yourselfer will run you $500 or so. Keep looking. To give ya an idea my bud has a 2000 evinrude 50hp with power tilt and trim and he's selling it for $500 with controls. no problems. you can find a good motor for that price if you look for a few weeks. $600 for a 40hp with compression issues will cost you a lot more in the end.

 

[JMailbox8]

Re: 1997 Mercury 40hp 4 cyl. Low Compression

Thanks guys. I think I will pass then. I am very familiar with 2 stroke engines, and have worked on more than a few outboards. I have done some small engine rebuilds, but from what I've seen, mercury parts aren't cheap. The one thing about the 4 cylinder that I am a bit concerned about is the number of cylinders. Stacked cylinders always tend to run hotter. I had a Polaris 3 cylinder snowmobile that had center cylinder cooling issues and required a new cylinder block, and I would imagine that this is the same deal with this mercury motor.

I could take a gamble and still get my money back in parts, but that is not my original intent. By the sounds of it, there's probably not a good chance that it is something simple. I've got a nice little 13' Boston Whaler that I'm rebuilding and I'm looking for a nice PT&T motor to go with it. This motor came up, but I think I'll wait for the next deal. Thanks again.

 

[sutor623]

Re: 1997 Mercury 40hp 4 cyl. Low Compression

Good call buddy. If you have $600 setting around you'll find something turn key for that whaler. And don't hate on the inline engines, but personally I prefer inline threes to the inline fours.