Ironhead Plug size

[Jumbo]

1972 XLCH 1000 Is a Champion R12YC correct ???

[CabritoLoco]

go here http://www.chopcult.com/forum/showthread.php?t=449 halfway through thread, follow link, chart covers em all.

hope it helps, good luck.

[Jumbo]

1972 XLCH 1000 Is a Champion R12YC correct ??? H8C !!! The dude at the auto parts store sold me a RN12YC Now trying to find out the differences to see if it hurt anything running that plug... The plug looks rich... black & sooty... So at least it wasn't running way too hot or lean..
Update: The Champion H8C plug is now called a 587 and the NGK cross reference is a BL6

[Robzilla]

Jumbo, I followed those charts and they aren't that helpful!!! I'm member of the QCB Forum and got some good advice from Crazyhorse Speed Shop"s Frank. The dude is a master at rebuilding heads and porting! I have a 1957 Ironhead and I just changed the plug wires and the plugs. I was running the Champion H8C, fouled those fuckers all the time and it was hard to start that old bastard. I was told by frank and forum member Papa, that I should be using the Autolite 85 or J12Y with points or RJ12Y with electronic ignition. I put in the Autolites and, Man, what a difference. Two kicks and it started! Used to take about 8-10 kicks with the champions. Runs smoother and doesn't seem to miss in the high RPM range.