Fuel tank securing nuts

[nialdavies1976]

Hi I have a 1961 G12CSR with the red tanknthat has the chrome panels, does anyone know what size thread is on the studs that secure at the front of the tank? my nuts have vibrated off (sorry) and I don't know what to replace them with.

Thanks

Nial

[Rob Harknett]

You should get correct bolts from club spares. Did you just nip them up so they worked as they should eg not tighten fully so they don't stop vibration? they should be wired on.

[1608]

Order two extra and use as lock-nuts. I found it far easier than trying to use locking wire.

[dave16mct]

Yes they are nuts not bolts and they are'nt wired on. Not sure of the size but they're nylocs, 5/16 or 3/8 cycle thread?
Dave.

[Mick D]

Hi

The fuel tank is threaded 5/16" BSC x 26 TPI and as far as I am aware accepts two bolts which are drilled to enable them to be wire locked together. If you have studs fitted it is fair to assume they are threaded 5/16" BSC x 26 TPI at the fuel tank end, however this is not necessarily the case at the other end, ( a carburettor to head stud is about the correct length but has one end 5/16" BSC x 26 TPI and the other 5/16" BSF x 22 TPI. Without knowing the exact details of the studs fitted it is impossible to help further. Why not return the bike to it's original configuration and install the correct bolts?

(Adding lock nuts will only be effective if the studs are secured into the tank in some way, (Loctite for example).

Regards Mick

[ajscomboman]

Mick on a 61 tank the two front mountings are not the same as earlier tanks which have a welded threaded plate. For 61 there is a deep recessed socket into which you insert a special rubber and special flanged bolt. The tank is then dropped over the mounting and using a washer and 3/8 BScy nyloc nut, the mounting bolt is pulled down and expands the rubber against the socket wall gripping the tank and holding it it place.

[Mick D]

Hi

OK - Sorry if I've caused any confusion, my 61 chrome trim tank is as I described and I thought this was the same across the range

Regards Mick

[ajscomboman]

Hi

OK - Sorry if I've caused any confusion, my 61 chrome trim tank is as I described and I thought this was the same across the range

Regards Mick

Not a problem, I suspect that if yours has bolts it's either earlier or modded.

[dave16mct]

Mick, at the rear of your tank does it have a bracket which extends backwards and is fixed with a bolt into a boss on the frame?
Dave.

[Rob Harknett]

As these fittings are not tightened up tight, they need to be wired on. Unless you prefer to keep replacing lost fittings. Good comment about studs and lock nuts, the lock nuts wont hold the studs in.