Pressure Check your Spark Plugs!!!----

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51Hog
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Pressure Check your Spark Plugs!!!----

#1

Post by 51Hog » Fri Jul 17, 2009 5:40 pm

Just found 3 bad plugs---2 new out of the box and one that I have been running for 2000 miles.
I was pressure testing the manifold assembly with 15 lbs of air.
When I misted dish soap/water mix to check the screws above the spigots, I soaked the top of the plug wires where the cups press onto the plugs.
After a couple of minutes, There appeared a pile of bubbles on the plug wire where it enters the cup that goes onto the plug. I cleaned it off, took the cup off and misted the plug with soap. It leaked at the top and the base of the porcelain.
Same with the other two plugs. Could be one of the great mysteries as to why one plug runs at a different color than the other. These were NGK.



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Re: Pressure Check your Spark Plugs!!!----

#2

Post by steve_wood » Fri Jul 17, 2009 5:59 pm

Wow. Who'd a thunk. Great tip!

Ohio-Rider
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Re: Pressure Check your Spark Plugs!!!----

#3

Post by Ohio-Rider » Fri Jul 17, 2009 6:54 pm

Where all three the same brand name?

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Re: Pressure Check your Spark Plugs!!!----

#4

Post by NightShift » Fri Jul 17, 2009 7:28 pm

Dear 51Hog,
You didn't close the intake valves?
Anyway, New NGK sux! Lucky it didnt burn a hole in your piston.

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Re: Pressure Check your Spark Plugs!!!----

#5

Post by boxtriker » Fri Jul 17, 2009 7:32 pm

I to have come across this with accel plugs before this is the one that came in my pan with a leak in it i switched over to NGK but you get about 1-2 duff plugs out of 10 with them as well not getting a spark from them
BOXTRIKER
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51Hog
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Re: Pressure Check your Spark Plugs!!!----

#6

Post by 51Hog » Fri Jul 17, 2009 8:25 pm

All three were NGK.
To tell the truth, I didn't even think about closing the intake valves. As long as there is 15 lbs. pressure indicated on the gauge on my manifold block off plate, it will get the job done. Any leaks past the rings will bleed out of the CC Vent.
Dale

boxtriker
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Re: Pressure Check your Spark Plugs!!!----

#7

Post by boxtriker » Fri Jul 17, 2009 9:10 pm

51Hog wrote:All three were NGK.
To tell the truth, I didn't even think about closing the intake valves. As long as there is 15 lbs. pressure indicated on the gauge on my manifold block off plate, it will get the job done. Any leaks past the rings will bleed out of the CC Vent.
Dale
Now that is weird i never come across a NGK leaking in that way in 30 years :shock: just that the number of duff ones per 100 has gone up over the years :D

boxtriker

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Re: Pressure Check your Spark Plugs!!!----

#8

Post by FlatHeadSix » Sat Jul 18, 2009 4:51 am

my experience with new production NGK is about the same as what has been mentioned above, they suck. In addition to the unacceptable failure rate and leakage they also appear to be resistor plugs (in spite of what the factory tech reps tell you).

I'm on the way to the AMCA meet at Wauseon right now so i don't have my notes handy but you can prove it to yourself by putting a digital ohm meter to the plug core. Compare a new NGK to a Champ or H-D plug and draw your own conclusions. For my money, leave the NGK's at the parts store for some other unfortunate loser.

jmho

mike

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