Petcock - trying to find a replacement for my 1981 Honda CB750K

[Jimbonaut]

Pretty sure the nut thread diameter on my petcock is 16.9mm (16.9mm? Who did that make sense to back in the day??) and it's knackered (full of varnish). Ideally I'd like to replace it with a straight exit petcock but coming up short on available options.

Anyone know how I can get adapt my the exit spigot thingy's thread on my tank to fit a different petcock? Without welding?

 

[redwillissuperman]

Pretty sure the nut thread diameter on my petcock is 16.9mm (16.9mm? Who did that make sense to back in the day??) and it's knackered (full of varnish). Ideally I'd like to replace it with a straight exit petcock but coming up short on available options.

Anyone know how I can get adapt my the exit spigot thingy's thread on my tank to fit a different petcock? Without welding?

You need to measure the OD of the spigot diameter and use a thread pitch gage (they come in tap and die sets and look like feeler gages with teeth) to determine if it's 1.0 or 1.5 etc.

 

[Jimbonaut]

Thanks man - the diameter is 16.9 and the thread pitch is 1.0

Thing is, not many petcocks out there that are a direct fit (one in fact that I can find). The straight exit petcock I like has a different diameter, and so I'm trying to figure out how to adapt what I got to make it fit what I want.

Any ideas?

 

[redwillissuperman]

Go to this page and it shows the specific way to measure and pick your petcock.

http://www.cb750c.com/Genesound/Petcocks_79-83_DOHC.html

Then we can see about adapting.

 

[Cookie]

https://www.siriusconinc.com/mobile/search-result.php?make=&model=cb750&part=2&partno=&search=search

Try these guys. There are even rebuild kits for your original, too!

 

[Jimbonaut]

Thanks guys, think I found an el cheapo replacement on eBay which'll hopefully do the job