1981 honda cb750 C. want to replace petcock

[cb360tj]

Hey My friend has a 1981 honda cb750 C. he wants to replace his petcock. Anyone know the size he needs? he says there are several options on ebay. (18mm or 16mm)?

 

[cb360tj]

This is the old one

 

[Red Fthr]

We're talking 2 mm here. I'm sure both would work fine. Find a parts number via a parts list manual or be very specific in your search including year and model if you want exactly what was used originally.

 

[Rich Ard]

We're talking 2 mm here. I'm sure both would work fine.

No.

He should measure what he has. That would be the size he needs.

 

[Hoosier Daddy]

Like Rich Ard says it's one or the other. It's the size of the tanks bung threads so only one will fit. Mother Honda went through several versions between '80 and '83 on the larger CB's so you need to verify.
According to http://www.cb750c.com/Genesound/Petcocks_79-83_DOHC.html ...
On an '81 tank it should measure 18mm part # 16950-461-771

 

[xb33bsa]

measure the bung hole spout spigot dealy on the tank with your digital calipers
push the on button first tho that may be the problem
but srsly if you don't have calipers handy use a wrench end(open end) or a six point socket to measure the diameter of the threads on the tank

 

[Red Fthr]

Word.