putting piston and ring in a 1978 v4 140

thespearstn

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Nov 2, 2003
Messages
29
i kept fouling plugs on one cylinder, now that cylinder has lost all compression. when it fouled a plug yesterday i saw some metal on the spark plug. this motor is a fresh rebuild. do u think the carbs caused this to seize. i got it unseized, but i was wondering if i can take the piston out by just removing the head, not the whole powerhead. thanks
 

walleyehed

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Jun 29, 2003
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6,767
Re: putting piston and ring in a 1978 v4 140

Good chance ya got something blocking a main jet to that cyl...<br />Ya gotta pull the intake manifold, but I'm not sure you can get it from there...<br />You may have some cylinder work to do as well.<br />Was the engine bored?? How much, and what pistons were used??
 

Dhadley

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Feb 4, 2001
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16,978
Re: putting piston and ring in a 1978 v4 140

Fresh rebuild? Why did it have to be rebuilt in the first place?
 

walleyehed

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Re: putting piston and ring in a 1978 v4 140

Is there any warranty on the "fresh rebuild"????
 

thespearstn

Cadet
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Nov 2, 2003
Messages
29
Re: putting piston and ring in a 1978 v4 140

same thing might have happened before. no i bought it off a buddy. i just cant figure what is causeing it to foul and finally seize.
 

walleyehed

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Jun 29, 2003
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6,767
Re: putting piston and ring in a 1978 v4 140

I think the "fouling" is contamination that is occuring before it siezes.<br />I would assume the carbs were done with the rebuild, if not, that is likely the cause again....If you choose to O/H, that carb is going to have to come off, tear-down and find the problem.
 

Walker

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Jun 15, 2002
Messages
3,085
Re: putting piston and ring in a 1978 v4 140

To pull a piston the powerhead has to come off and the cases split. Pull the head off now though and survey the damage.
 
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