Yamaha tri-z Sparkplug question

[Karhu]

Dear all,

Today a friend of mine came over and we checked out my tri-z. I was telling him about how i rebuild it and bla bla bla..

Now we took a look at the sparkplug and he was wondering why i had a thick shaft on it. He's a dirt bike specialist and advised me to just put the original spark plug. So i told him this was the original as i looked it up in the service manual of the triz...

Now could it be that there are two NGK B8ES? One with small and one with thick shaft?? So now im just wondering what spargplug should be best for my triz....

Thanks already!!

Piet

[muthey]

there are two comparative ones the ngk br8es, and the honda ngk br8eg I have found the regular ngk br8es holds up much better for my use, and I run slightly rich all the time.

[TLANEYYZ]

According to the NGK book....B8ES - regular/B8EVX - VX type/BR8ES - resistor type. gapped at .028". This is a non-projected insulator, 14mm thread diameter, 3/4" reach, 13/16 hex plug.
for a ytz250