1998 Johnson 225 Rod Knock????

R

Richard Guedry

Recruit
Joined
Nov 26, 2012
Messages
1
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....I can't find the article anymore.
 
B

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: 1998 Johnson 225 Rod Knock????

You most likely got a bad wrist pin or connecting rod bearing. Don't run it anymore until you find the prob.
 
Faztbullet

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,618
Re: 1998 Johnson 225 Rod Knock????

+1
I thought I read that these engines had a problem when they first came out with bolts backing out of rod/main caps.
Click to expand...
That the main bearing end caps on block, not rod bolts
 
D

daselbee

Commander
Joined
Jan 20, 2009
Messages
2,765
Re: 1998 Johnson 225 Rod Knock????

Pull the plug, rotate the flywheel manually til the piston starts to go down in the cylinder.
Stop rotating, and using a screwdriver, long extension, wooden dowel, some sort of substantial tool,
push down on the top of the piston thru the plug hole.
You should get NO movement. Movement indicates wrist pin or bearing problem.
 
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