Spark Plug Diameter/"reach"

[metalforever]

I need to find out the pluds thread diameter (Also know as the plugs 'reach') so that i can buy a compression tester that fits the bike.

Anybody know what the thread diameter is in cm/mm?

Thanks in advance!

[gsJack]

Standard DPR8EA9 plug has 12mm dia thread with 3/4" reach:

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

[beRto]

I need to find out the pluds thread diameter (Also know as the plugs 'reach') so that i can buy a compression tester that fits the bike.

Anybody know what the thread diameter is in cm/mm?

Thanks in advance!

Hello metalforever,

The stock sparkplug is made by NGK; the sparkplug code is DPR8EA-9

You can cross reference that code against a reference table:


Based on this reference table, we can obtain the following information:

D	12 mm thread diameter
PR	projected insulator; resistor
8	"cold" rating
E	19 mm reach
A	special construction (details not specified)
-9	0.9 mm (0.036") maximum gap

I hope this answers your question!

More info available at:
http://www.kaila.net/tl125/tl125ngkcode.html