which plug?

[rowdyrandy]

I picked up a pair of BP7ES plugs the other day while I was out for my 75' - got home and to my suprise the plugs already in there are B8ES's, and the BP7's are considerably longer, but I was sure I had seen somewhere that the BP7ES was correct for the 650b's. Then it came to me; Mikes has the BP7's listed for the 75's and both my clymer and original maunal say B8's...can I use the new plugs or should I go out and get a pair of B8's? The bike is stock except for a set of unis and a mac 2 into 1.

 

[jay760]

I think the xs1/2 were B8ES, I always use BP7ES.

 

[SCHMEEL]

just looked it up in my Haynes shop man. heres word for word what it says under Sparking Plugs ,type - "B-8ES (XS650C models BP-7ES)

Equivalents- Motorcraft AG 2 - XS 2 models
AG 1- XS650 models

 

[jay760]

In the back of the Haynes manual, for all the later models it states, models D, E, S, SE, SF, 2FG, SG, use BP7ES or Champion N7Y, or UK models BP8ES

 

[5twins]

The "P" in the BP7ES stands for projected tip. The center electrode sticks out more from the threaded portion and this is supposed to give a better burn. '73 and older engines had different pistons so maybe they do require the plain "B" type plug but your '75 has the same top end parts as the later models so you can safely use the "BP" plug. I would for the possibility of getting that better burn. Also, the one step hotter 7 should burn cleaner.

 

[rowdyrandy]

thanks 5twins, thats exactly what I was looking for.