water droplet on spark plug.

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bamaj

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working on a 1994 40hp force,adjusted carb this morning per advice on this forum,got it running smooth.let idle awhile and it would start running on one cylinder,rev it a little and it would clear up,then do it again.pulled the plugs and bottom cylinder had couple small drops of water,cleaned it and tried again and same thing with droplets on bottom plug.where should I start looking to find where water is coming in cylinder?128&130 compression on cylinders. thanks in advance.
 
Frank Acampora

Frank Acampora

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Re: water droplet on spark plug.

Its either a head gasket or the exhaust cover gasket. The head is easier to remove so check that first.
 
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bamaj

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Re: water droplet on spark plug.

by checking it means pulling and replacing head gasket,correct ?
 
MickLovin

MickLovin

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Re: water droplet on spark plug.

probably wouldn't hurt to have one at the ready.
 
Frank Acampora

Frank Acampora

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Re: water droplet on spark plug.

Pull the head and check the gasket. If it is good, it usually will be reusable. The exhaust cover gaskets usually do break when you remove the cover. be careful with the exhaust cover bolts they tend to be corroded and some may snap on you.
 
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bamaj

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Re: water droplet on spark plug.

am going to pull head t'day , if it's questionable I will order new one and go from there.thanks
 
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bamaj

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Re: water droplet on spark plug.

took head cover off and the lower right corner bolt was not torqued down like the others were,the metal part of the gasket was not stuck to the head where that bolt was, every where else the gasket is stuck to the head.should I replace the gasket or try old one making sure to torque it to specs.what are the torque specs on head bolts.
 
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Frank Acampora

Frank Acampora

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Re: water droplet on spark plug.

If the gasket appears to be good, I would try to re-use it.

Head bolt torque is about 280 inch pounds if 3/8 bolts (9/16 heads). You tighten all the bolts in two or three stages until final torque is achieved. For example: Tighten all bolts to 100 inch pounds then go back and tighten to 200, then to 280. You start in the center of the head and work outward in a spiral pattern.
 
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bamaj

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Re: water droplet on spark plug.

there is more water on the plug now that I put the head back on,so I'm going to assume that the head gasket is bad.i will order one t'day and put it on and see what happens.if it has water after that I'll go to the exhaust gasket.
 
MickLovin

MickLovin

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Re: water droplet on spark plug.

The water on the plug, was it the same cylinder as where the head wasn't torqued down? and did you see any marks of where the water may have been getting pasted? Just interested in your findings thats all.
 
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bamaj

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Re: water droplet on spark plug.

yes,same spot.didnt c any markings where it may have been coming through,but with the gasket loose at the same spot where bolt was not torqued makes me think that water was coming in there.the gasket also seemed a little moist at that spot.
 
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bamaj

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Re: water droplet on spark plug.

is ther any thing I should do before I put the new head gasket on tomorrow,I've been cycling the motor to get the water from behind the piston, also should I try to clean the carbon off the piston or just do a decar after I get it back togather.
 
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bamaj

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Re: water droplet on spark plug.

new head gasket not sealing,leaking water all the around head,was not with old gasket.no sealer was on old gasket.torqued to 100,200 than snugged to 240,any suggestions.thanks
 
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MickLovin

MickLovin

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Re: water droplet on spark plug.

Can I ask, is your fuel ok and do you have a water separator or filter before it gets to your carbs?
 
jerryjerry05

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Re: water droplet on spark plug.

Did the head ever get hot or you overheat the motor?
Possible the head is warped?
The easiest way to check is remove it and mke sure it's clean and put a straight edge on it.
Or a piece of glass. Glass is pretty flat.Use a feeler guage to see if it has any warped edges???
You need to make sure the old stuff(melted gasket) is completly gone fom the mating surfaces.
Don't try to de carb.Wait for the cylinder to be operational.
Pics of the parts might help?
 
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pnwboat

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Re: water droplet on spark plug.

Are you sure it's the correct head gasket and it's installed correctly? Never heard of a gasket leaking like that unless it was the wrong one.
 
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bamaj

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Re: water droplet on spark plug.

head lays flat on piece of glass,no movement,head gasket matches one that came off of it.i matched the numbers last night to the numbers on the mercury parts diagram.its a sierra gasket.Mick-gas is a week old,cleaned tank before using.water only in bottom cylinder when I started this, now there was a little in the top cylinder.thanks.
 
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