Spark plugs cracked

superjetnj

superjetnj

Location
Jersey
Went to ride my SJ yesterday and it had a terrible miss. Ran great last weekend, So I decide to change the plugs and found that both plugs cracked from the nut to the terminal. No crazy set-up b-pipe, pro-tec head, 175 psi, single 46. Anyone have any ideas?
 
X

X2Kid

Location
Canberra, Australia.
My only experience of this was when I was tightening the plug and I heard the 'crack'. Wondering if you tightened them up just below this threshold and the stress from running has tipped them over the edge?

I'd install brand new plugs as per manufacturer's spec's and see how you go. If the problem occurs again the issue is elsewhere.
 
superjetnj

superjetnj

Location
Jersey
Sure it could be, but I've had this engine combo for 3 years without an issue like this. Always have run super, 1 oz klotz booster per gallon to keep the fuel fresh. Any other thing that I should be looking for? Stock ignition, maybe a colder plug? Or should I change back to the oem head and gasket and call it a day?
 
x2mafia

x2mafia

Maximum effort
Location
WA
what do you use to install your plugs?

spark plug sockets are OK but somtimes the headpipe or filters make you come in at a funky angle. I use plug specific sockets for work (automotive) but for all the toys I use this wrench from motion pro. It puts no stress on the top of the plug.

http://www.motionpro.com/product/08-0147

It could have been cracked since original install. Then the compression took over and finished it off after time. There isnt much metal around to short to ground since our spark plug boots are pretty efficient and that may be why it didnt fail immediately.
 
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BrightE's

BrightE's

Paul
Location
Seattle, WA
Only time I've had it happen was deto from my timing being too advanced. Kept breaking them and almost seized my motor until I fixed the timing.

Sent from my RS988 using Tapatalk
 
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