Woah, old plugs

[deviantspeed]

Found these tonight, the kicker was that they were about 3/4" and I had to use wrench to get them out. Threads matched (thank god, I was worried about something impacted in there) They were NOT standard 11/16" or whatever the next sized up spark plug socket was!

Well, an open end wrench on the front, but didn't mess around with the rear, just grabbed a 19mm socket and took the rear on out.

PO fail on these, or were these recommended at some point?

 

[nemoxb]

Well stock OEM plugs are 5/8 (champion) just depends on who makes them. Like I think auto lite is 11/16 for example.

 

[deviantspeed]

3/4" installed, got a shot of the p/n.

11/16" didn't remove them, as stated above.

Stock should be 5/8". Just really surprised these were installed. NGK D7EA.

 

[crawfo]

Those are 18mm plugs. A lot of metric v twins and v fours use plugs that are that size. I am pretty familiar with them because I came to Buell from VFR's. No worries, the threads are the same..