1998 Johnson 225 Rod Knocking??

[Pocket]

I just purchased this motor and it sounds like a rod knocking...its the top cylinder, it has 110 psi on compression. When I remove the.spark plug I don't hear it anymore. I thought I read that these engines had a problem when they first came out with bolts backing out of rod/main caps.. if so was this a common problem with that model..I can't find the article anymore. This is a Carb model, Thanks in advance for any info

[boats.net]

It's possible but would have to take apart to tell.