spark plug

[Jnblaster05]

what spark plug do you suggest for a 440 11to 1 compression i mean is there any diffrence really in atv plugs

[scuzz]

I'm not positive, but I assume you would want to run a colder plug.


My buddy never had issues with his stock-plugged 440 with 11-1.

[drew416ex]

I like running a dpr9z, its the coldest plug ive seen for it. I can tell a difference on hot days. Seems to run a little cooler.

[greenblood01]

I'm not for sure, but I don't believe a colder or hotter spark plug will affect the engine temperature enough for anyone to notice. I would stick with the stock DPR8Z, you will most likely have much more trouble fouling plugs with a 9, especially if you don't always allow the engine to come up to temperature.

[TRXRacer1]

Originally posted by greenblood01
I'm not for sure, but I don't believe a colder or hotter spark plug will affect the engine temperature enough for anyone to notice. I would stick with the stock DPR8Z, you will most likely have much more trouble fouling plugs with a 9, especially if you don't always allow the engine to come up to temperature. 8 or 9 the spark is the same. The difference is how the plug is insulated from the head. Shouldn't make a difference for fouling but I do agree you'll have a hard time telling a difference.

[greenblood01]

That makes more sense, thank you TRX.

[TRXRacer1]

Originally posted by greenblood01
That makes more sense, thank you TRX. NGK has a very good tech write-up on their web page about heat ranges and what the goal is behind them. I learned a lot when I read that one.

[greenblood01]

I'll have to check that out. It would be nice to be able to give customs a valid reason as to how a "hotter" plug won't make their quad faster.

[Jnblaster05]

thanks guys