Does anyone know what the exhaust header stud thread pitch size is on the SC21?
I have one original stud remaining (the rest have been butchered) and the thread has just stripped on the nut. I have a feeling the previous owner hasn't put the correct size on.
so yeah, i just need one new nut and typically i cant find one that fits in my box of random nuts.

 

Hi dougyb83, welcome to the forum.
Please pop over to the new members area and introduce yourself with a bit of history and we would love to see pics of your bike

Re: your specific query----
Nuts Appear to be 7mm No. 22 on this page.
https://www.ronayers.com/oemparts/a/...a3f665/muffler

 

Yea, but unfortunately that doesn't tell him what the thread pitch is. Probably going to take someone that has one and check it.

 

I'm pretty sure the pitch is1.00 for the nut.

 

Best to determine stud threading with actual pitch gauge so you know for sure. Can get these at any auto-parts store for $2.99. Extremely useful.



If studs are buggered, might as well replace them. When threads are too damaged for double-nutting, I just weld nut onto end to remove. Heat up where it goes into block with torche to expand aluminium and it comes out easily. Some bikes, like my VFR uses dual-sized studs, with 8mm in block and 7mm header nuts. Easiiest just to buy factory OEM parts. Otherwise, remove remaining good stud and measure carefully.