What spark plugs should I be using?

[Blue Dave]

I have never fouled a plug on my Apex but then again I have followed the advice of others regarding the need to fully warm up the engine before shutting it off.

Here is a link to a thread about this subject.

http://www.ty4stroke.com/viewtopic.php? ... park+plugs

 

[RX1Jim]

Anybody running the NGK or Denso iridium plugs in their sleds? I am thinking of trying them in the 10 heat range. I know they offer a plug in the 9 heat range.

 

[littleredsled]

like last year the guy i bought it off moved it out of his garage and accidentally hit the kill and it fouled 2 plugs and ya so dont kill it and start it all the time like i mean just start it and let it warm up for a while and then move it back in or whatever your doing with it.

 

[**sj**]

Anybody running the NGK or Denso iridium plugs in their sleds? I am thinking of trying them in the 10 heat range. I know they offer a plug in the 9 heat range.

I am running the denso equiv to the cr10ek's....no prob's...but not sure of the benefits either

 

[littleredsled]

just bought the plugs today 70$ for 4 canadian!!!!! wow there expensive

 

[JROCK]

Im sure this has already been pointed out but how come everyone is running the CR10ek's instead of the CR9ek's. i read that they would have the same hp gains but would have the same heat range as the stock plugs. This would eliminate the cold fouling as i have never fouled a stock plug.

 

[**sj**]

cr10ek's are a 2-3 horsepower improvement over the cr9ek's....if left to properly warm up before stabbing the throttle fouling is all but non existant

 

[Blue Dave]

The CR10EK's are a 2-3 Hp improvement over the CR9EK's or the stock plugs?

I had assumed that the HP increase comes from the dual electrode and not the colder heat range.

That has made me wonder why not the dual electrode CR9EK instead of the stock single electrode plug.

 

[**sj**]

nope...its the 10's for all fourstrokes =2-3 h.p.

Order them from al ulmer at ulmer racing !

 

[JROCK]

I had assumed the same thing as blue dave! 2-3 hp over stock and not between the 10's and the 9's.

http://www.mototuneusa.com/two_free_horsepower.htm

 

[**sj**]

good link...however our machines have supposedly been dyno tested by ulmer and he says the 10's...I'd like to know if anyone knows about the 9's as well on our machines?
allen..chime in?

 

[The Snow D.O.]

Someone mentioned before that the 10's sit slightly lower in the cylinder and may build carbon deposits on the few threads that sit exposed in the chamber making it difficult and or problematic removing the plugs. Anyone experience this? and if so, what should be done to prevent any damage?

 

[The Snow D.O.]

ttt

 

[**sj**]

jrock saw the info in your link...interesting...I would think remove them annually and wire brush the carbon off the threads well....now I'm curious on the 9 vs. 10 thing as well!

 

[Blue Dave]

TTT

Do the CR10EK's threads actually extend further into the combustion chamber than the stock plugs?

If so, should they be removed and the threads cleaned of carbon deposits as part of yearly PM?