Would the wrong spark plugs cause...

[jasonhart]

my boat to overheat? Took them out today and discovered they are wrong. They look good though, nice light brown color and all of them are consistent.

 

[z1nonlyone]

Re: Would the wrong spark plugs cause...

In my opinion, yes. We bought our boat and soon after had to rebuild the 5.7 engine as we had a "pistion slap". After doing some investigation, and talking to a professional engine builder, he noticed that the spark plugs were the wrong type. They were too long and supposedly, therefore were too close to the exhaust valve. This caused the exhaust gases to heat the spark plug electrode and act like a glow plug causing preignition.
Make sure you use only the plugs recomended by your engine maker. At least as far as heat range and physical type.

 

[jasonhart]

Re: Would the wrong spark plugs cause...

Mine were definately wrong. Had NGK UR4, changed to what is recommended, Ac Delco MR43T. The insulator on the NGK's sticks out into the cylinder alot farther. My overheating problem has been kickin my butt good. Hope this solves my problem.

 

[Fishermark]

Re: Would the wrong spark plugs cause...

I cannot imagine the plugs being the cause of your problem.

What have you done to solve it to this point? Impeller? Checked manifold / riser?

 

[jasonhart]

Re: Would the wrong spark plugs cause...

Yes yes and yes. Not a cooling system problem. Hard to say if it's the plugs or not. Won't know til this weekend on the lake where I can put it under load. The only other thing i could think of is a blown head gasket...as far as following the manual on troubleshooting. Might as well pull the whole motor if I go that far. Have to remove alot of stuff.

 

[JetBote]

Re: Would the wrong spark plugs cause...

Too much timing can also over heat your engine

 

[Howard Sterndrive]

Re: Would the wrong spark plugs cause...

Would the wrong spark plugs cause
my boat to overheat?

no, spark plugs cannot make your engine overheat

 

[TiredoleBoy]

Re: Would the wrong spark plugs cause...

Depending on the plugs, it will burn hotter or cooler. I know when I built race cars, we would experiment with plugs to see what would make the car run at its optimum. So there could be a possibility of the plugs causing it to run hot. But perhaps not enough to cause it to overheat.

 

[Howard Sterndrive]

Re: Would the wrong spark plugs cause...

What year make and model 5.7 are we talking about? - what drive system?

 

[z1nonlyone]

Re: Would the wrong spark plugs cause...

What year make and model 5.7 are we talking about? - what drive system?

If you are addressing me, my 5.7 EFI was out of a 1997 chaparral 1930 w/alpha one, gen 2.

 

[z1nonlyone]

Re: Would the wrong spark plugs cause...

What year make and model 5.7 are we talking about? - what drive system?

If you are addressing me, my 5.7 EFI was out of a 1997 chaparral 1930 w/alpha one, gen 2.

 

[sethjon]

Re: Would the wrong spark plugs cause...

You are wrong. Plugs can definitely do that and cause severe problems.

 

[6meter]

Re: Would the wrong spark plugs cause...

In my opinion, yes. We bought our boat and soon after had to rebuild the 5.7 engine as we had a "pistion slap". After doing some investigation, and talking to a professional engine builder, he noticed that the spark plugs were the wrong type. They were too long and supposedly, therefore were too close to the exhaust valve. This caused the exhaust gases to heat the spark plug electrode and act like a glow plug causing preignition.
Make sure you use only the plugs recomended by your engine maker. At least as far as heat range and physical type.

"piston slap" happens when there is to much clearence between the piston skirt and cylinder wall. NOTHING to do with what plug your using. Neither would a plug that was to long. Sound like you got fed a bunch of b$ll.

 

[Howard Sterndrive]

Re: Would the wrong spark plugs cause...

You are wrong. Plugs can definitely do that and cause severe problems.

1. sorry- not a chance his engine overheated simply because it had UR4 spark plugs in place of MR43T
(unless they were so long they hit something in the combustion chamber, but that's a mechanical failure -not overheating)
2. you don't even know what engine it is and neither do I, the OP should read the suggestions for successful posting in this forum

how to ask a question:
http://forums.iboats.com/showthread.php?t=220416

 

[jasonhart]

Re: Would the wrong spark plugs cause...

Sorry to all....350/260hp mcm, 1984 23' chris craft scorp. I really don't think that will fix my problem either. Thinkin that maybe the previous owner advanced the timing a bit and the champ. rv15yc4 plugs that he he put in there were a bit hotter than factory spec. Put AC Delco MR43T's back in her. Come on Saturday>>>>>!

 

[jasonhart]

Re: Would the wrong spark plugs cause...

...understand 'piston slap'...and that's not a problem. Plugs looked good and burning consistent. Did a compression check when I first started having problems and nothing was amiss. But a blown head gasket may not show up then...was not under a load. Problem has been kickin' me a**...but I've learned alot about my boat.