75hp force spark plugs

[jpsurf]

I noticed my spark plugs have this "oily film"on them @ end of a day..not sure what made me check em.moter runs good..is this normal? Top 2 were exactly the same & cylinder 3 was less..i add startron to my fuel & thats all..
1st picture is after i wiped off with my finger
2nd picture is right out of the motor. .

 

[Jiggz]

The 2nd pic shows some signs of water droplets unless that is due to the fuel additive. Normal working engine with normal working plugs do have some little fuel oil mix wetting due to the fact these motors are 2 cycle motors. If the motor is running fine it could just be the fuel additive. Check the plugs again when you have new fuel oil mix in the tank and see if the "water droplets" go away. If not you might want to check compression on all three cylinders.

 

[jpsurf]

Thanks jigs..that was my first thought..water or from the additive..compression was perfect 4 months ago..i did have water & crap in my seperator & tank..But i flushed the tank clean & changed the seperator & all fuel lines..boat sat & only used a few times a year since new...

 

[jerryjerry05]

No Title

How old?Salt or Fresh?
​Any additive should mix with the fuel and not show on a plug.
Do a comp test.

You flush after each use?

Even in fresh water it should be done.
IF?? it's possible you hit sand at any time it needs to be flushed.
Pic is a motor that wasn't flushed and salt ate the gasket and lots of the alum.
​

 

[jpsurf]

Thx for the reply..
It is a 96..
Never ran in salt water..nor do i flush..Im never near sand..
Now im worried..
Ill do a compression test..
Would i notice any other signs water is getting in?
Motor starts right up..little rough when shes cold but Runs great all day after that..

 

[Jiggz]

If there is water intrusion into a cylinder and the amount is minimal, it will likely cause the spark plug to be clean as a whistle due to steam cleaning action during combustion. However, if the water is more than minimal, it should caused some misfires hence the spark plug will be wet because not all of the water is converted to steam. A good compression basically indicates the head gasket, rings, pistons and cylinders are intact or good working order.

However, that doesn't mean with good compression you cannot get water intrusion. Yes, it can intrude from the exhaust port if the exhaust port gasket or plate is leaking water from the water jackets. Don't worry yet instead try doing a process of elimination from the easiest to the hardest, . . .gas, gas tank, or it could just be condensation. Test run the boat on the driveway and then check the plugs again.

 

[jpsurf]

Jiggs thanks for the reply..
Motor has been giving me problems.
Plugs keep crapping out on me every few trips
My mechanic mentioned the exhaust plate gasket after he just changed the head gasket
Motor runs rough @ idle & in gear
I used to get 5200 rpm out of her now only 4800 & just doesn't run smooth anymore.

Is changing the exhaust plate gasket a "major" job..

 

[jpsurf]

Top cylinder

 

[jerryjerry05]

Nothing wrong with the plug.
​Shows oil and some carbon.

Did he do a compression test after the head gasket?

Do one anyway. Post results.
Do a spark test.

Pull the carb and check the reeds.
Check the diaphragm in the fuel pump.

Your choke/enricher could be feeding too much fuel.
After it's started pinch off the line from the enricher and see if that helps.

IF??? you really don't ever hit the bottom and suck up sand then I'd say the exhaust chest shouldn't be clogged.

It's a fresh water motor and the screws on the exhaust shouldn't be too hard to remove. Start with PB Blaster now and spray for 3-4 days before you start the tear down.

Rough running on cold startup: that's normal.

This 3cyl with 1 carb isn't the best design from Force.
They tend to score the top cyl..
Just make sure you run a good oil and enough oil.

 

[jpsurf]

Thx for the reply jerry..
What would be the milky coating around outer ring be?
The plugs are brand new & maybe an hour @ best of run time on them..
I have had 2 mechanics say it looks like water on the plugs..
The boat has been to 3 mechanics for this same issue.all 3 changed the plugs & "messed" around with the carb..Im no mechanic but to me its not the problem..all 3 times its only been a bandade to the "real" issue..
Thanks

 

[tommarvin]

It's time to stop throwing $ at the motor and start testing.like the guys above say to do.
Do a compression test, if you don't have one consider buying a leakdown tester at HF tools for 40 bucks.
You probably will snap bolts off if you remove the exhaust plate, it's part of the game..

 

[jerryjerry05]

Didn't see milky coating??? Where?
​ANYTIME you have milky anything, there is water intrusion of some kind??
​Do the compression test.

Take the exhaust chest cover off.
Sounds like either the new head gaskets not on right or the exhaust chest is leaking?
Ever overheat real bad?

I had a problem with one motor, kept missing, did a comp test.
All had 145#
Then I noticed 1 tiny drop of water on the plug.
Turns out the head gasket was bad, had a tiny,tiny bad spot.

I have seen exhaust chest gaskets go bad too.

Just worked on the neighbors 50Mercury. Kept running bad and fouling out one of the plugs.
Tried EVERYTHING I could but ended up taking the whole motor apart.
Even stripped down I couldn't find anything.
Then I saw a scratch or what I thought was a scratch.
Turns out it was a cracked block. Shot motor.