spark plugs question

A

andrewinfl

New Member
ok,

I have a new 2 stroke 66cc engine. I went and bought a bpr7hix ngk iridum spark plug for it.

I noticed it was a little longer in the threads. I read all about it. Some say the stock one is too short. I had the head off and confirmed the stock one being to short. My bpr7hix looked to fit better.

Will the bpr7hix plug be ok for my engine? Scared to ruin a new engine.

thanks
 
As long as there is no interference with the piston the longer plug won't hurt anything.
Install the plug after you have installed the head and torqued it down. Slowly rotate the crankshaft through a full revolution. If the piston doesn't touch the plug you're good to go.

Too bad you wasted your money on that high dollar plug however. There is no evidence that they improve performance. They are designed for high milage. Not performance gain.

Tom
 
yes, they are big enough to actually increase compression a bit - if it doesn't hit your piston and you are not already getting too much compression, they seem to work well
 
Thanks for the replys guys. I will try both the stock and the bpr7hix and see if Ican feel a difference. Stock plug costs what, 3 bucks. My iridium ngk cost me 9 bucks. I trust ngk plugs. I have had a spark plug break a wreck one of my engines.

Also in motocross we used iridium plugs, I thought that were more resistant to fouling out too.

Also for sure I'm getting more compression.
 
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Spark plug fouling shouldn't be a problem if your fuel to oil ratio is good and the fuel to air mix is right and the piston rings aren't worn out.

I've always found it funny that a selling point for spark plugs or expensive ignition components is that they will fire through fouling or heavy oil residue. My contention is that if you have the conditions that cause plug fouling, you have bigger problems and need to address those instead of spending money on ignition band-aids. :)

Tom
 
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