125 Force bad cylinder question

M

mysbrand

Recruit
Joined
Jul 11, 2004
Messages
4
I'm new to owning a boat (1988 Bayliner Cobra is my first) and have a (probably stupid) question: I had the boat into a shop because it would not stay running, the mechanic said the number 2 cylinder is shot. He did a compression check and said 1,3,4 cyliders were running 125 - 135 and #2 is around 40. If I have to have the #2 cylinder rebuilt, will all cylinders need to be done, even though they are ok? Thanks in advance for any help you guys can shed.
 
W

wilkin250r

Chief Petty Officer
Joined
Feb 9, 2003
Messages
570
Re: 125 Force bad cylinder question

You can't remove just one piston to rebuild. And as soon as you remove the piston from the cylinder, you almost HAVE to replace the rings.<br /><br />Now, you may not need to replace the pistons on the other cylinders, or bore out the cylinder (each adds expense) but you certainly need to replace the rings and hone the cylinder. So yes, you need to rebuild all cylinders.
 
S

seldont

Petty Officer 2nd Class
Joined
Oct 4, 2003
Messages
110
Re: 125 Force bad cylinder question

If I am not mistaken on the 4 cylinder Force and Chryslers you can remove the head, then the carbs and intake and unbolt one rodcap and push the piston and rod assembly out. The only reason one may want to do it this way would be in case there was no cylinder wall damage. You could do a very light hone on it and install the piston assembly. However the first thing I would do would be pull the head and check for a blown head gasket. While it is off turn the flywheel by hand and check for any visible cylinder scoring. Then, if necessary remove the offending piston assembly. All of that being said just like anything else if you really want to do it completely right remove the powerhead and do a complete teardown.
 
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