Spark Plugs

[Anonymous]

I've got a slightly modded 250, 2bbl, header and cd ignition. I was looking at the latest Summit catalog, and the list a handfull of different spark plugs. Are there any noticeable performance difference's in these plugs?
Thanks,
Ken

 

[wallaka]

Probably not. By and large, plugs are just plugs. Kind of like gas. You know if you've got a bad set (or tank), but you won't notice if you get a slightly better grade.

 

[wsa111]

Ken, i have had very good luck with NGK irridium. They are pricy but they have the pin center electrode to promote better firing.
Autolite single or double platinium are less pricy & are fine.
Accel is the least expensive. Bill

 

[rbohm]

8) these days you might find 1/2hp or so between plug brands. this of course is assuming the engine is in good condition to begin with, and all the plugs are properly indexed to avoid one plug having an advantage over another.

 

[Anonymous]

The biggest benefit in running different spark plugs is if you are running a high performance engine and the normal plug is getting so hot that it glows and forms a hot spot causing pre-ignition. In this case you would have to use a colder grade of plug where the centre electrode is shorter and not exposed to so much heat. Run a plug which too cold and the engine will be hard to start and not work very well in general.

The difference between different spark plug manufacturers of the same heat rating is very small in my opinion.

Tom

 

[XPC66]

From my experience with turbo engines, plugs do vary markedly between brands. Even going from dual prong to single can cause the engine to misbehave. I'm not sure indexing is all it's cracked up to be though.

 

[addo]

Has its place. I've one engine where a mis-indexed plug will be tapped shut by the piston crown.

 

[rmoe88]

Another place i have found spark plugs making a huge difference is on two-stroke dirtbikes, but not in terms of power. On my ktm 200sx, i have run both normal/cheap spark plugs (a few brands) and also NGK irridiums. Normal plugs foul out MUCH quicker than the irridiums. I dont know why this is, but nothing sucks more than climbing a steep hill to have the plug foul out half way up. Since i only have one plug on the bike, i now use only irridiums on it

 

[Harte3]

http://speedtalk.com/forum/viewtopic.php?t=10755

A two-page thread on plugs there...interesting.