Banjo bolt thread

[htown16]

I manage to strip the threads on the hole for the banjo bolt on the timing cover. I want to helicoil it but I can't determine the thread size. Neither sae or cei nuts fit onto the bolt. It looks close to a 5/16x20 sae but not quite.

 

[madass140]

5/16" BSF

 

[htown16]

Thanks, got a helicoil kit ordered. Hate having to pull the cover but hopefully this will fix the only oil leak on this bike.