spark plugs

[benny hedges]

just some info on spark plugs to explain all those numbers & letters.

http://www.ngksparkplugs.com/docs/tech/ ... _plugs.pdf

codes for all the other major brands & lots more info
http://www.spark-plugs.co.uk/pages/tech ... hnical.htm

manufacturer's cross reference charts
http://www.sparkplug-crossreference.com/

considering experimenting with hotter plugs in mine to reduce engine temps with the state of tune im running...
had good results doing this in the past with 2 strokes so will probably start by dropping from a 9 to a 7 & see how it runs.
(when it's back together that is!)

[Jonesey]

I've got some 8's if you want to try those too- save a bit of £
Chris.

[benny hedges]

cheers m8... already ordered some from aceparts.com
did you notice it ran any cooler?
i just think it will help cos of the cams, advancer & pistons....

[seb421]

Which plug would you recommend for a standard storm mate?

Currently using the DPR9EIX-9

Would it make any difference changing to a DPR8, would i notice a difference if i went the other way and used a 10?

[lloydie]

Dose anyone know the NGK iridium
Plug number for the firestorm ?


Sorry officer
The voices made me do it

[benny hedges]

DPR9ETX-9

£5.95 from aceparts, free delivery. tenner everywhere else at least, plus postage.

[lloydie]

Thanks benny )


Sorry officer
The voices made me do it

[oldbikeman]

Don't use a 8 as that is a hotter plug.You would need a 10 and I'm not sure they supply them .DPR9EIX-9 is the latest plug.But any D9 size is safe only the quality (materials)is improved .A D9EA has the same rating.

[benny hedges]

Don't use a 8 as that is a hotter plug..

running a hotter plug has the opposite effect on the engine than what you would expect.
running a colder plug will make the engine run hotter

when they say a hotter plug, they are refering to the actual temp of the core of the plug, so say a 9 runs at 350c, and a 7 runs at 425c, less energy is needed to ignite the mix with the 7... does that make sense?

only know this as i experimented with different plug temps when racing 2 strokes cos i had a habit of melting pistons though detonation caused by high compression & running too cold (or hard) a plug...
doesnt really make a difference in performance, apart from reducing the pre-ignition but does definately make a difference to combustion chamber temps, which is why i was considering having a play with the numbers

[seb421]

Don't use a 8 as that is a hotter plug..

running a hotter plug has the opposite effect on the engine than what you would expect.
running a colder plug will make the engine run hotter

when they say a hotter plug, they are refering to the actual temp of the core of the plug, so say a 9 runs at 350c, and a 7 runs at 425c, less energy is needed to ignite the mix with the 7... does that make sense?

only know this as i experimented with different plug temps when racing 2 strokes cos i had a habit of melting pistons though detonation caused by high compression & running too cold (or hard) a plug...
doesnt really make a difference in performance, apart from reducing the pre-ignition but does definately make a difference to combustion chamber temps, which is why i was considering having a play with the numbers

Very informative mate, thumbs up!

[oldbikeman]

A hot plug (low number) holds it's temperature to burn off fuel combustion deposits .A cold (high number) releases heat faster to prevent detonation and tip melting.The correct plug should be chosen to just be running hot enough to burn off black soot deposits and be a light tan colour.