1960 Fuel tank fixings

[ixonchitts]

Hi,
Have a query re the front fixings on my fuel tank. The bike is a 1960 G9 frame with a 1959 G12 engine. I dont think the tank is the original but appears to be correct for a 1960 duplex twin.

The front fixing bolts dont appear to be right though, having a screwdriver flat head slot, and a hole at the base (close to the tank) - see pic. I have tried to remove them as I'm sending the tank to be cleaned but they just turn - possibly the thread has gone, and intend to replace with the correct fittings. I'm looking for advice on,
1. What should the correct bolts be ( 014997 with hole through the Hex?)
2. What is the thread on the correct bolts?

Thanks in anticipation.

Steve

[dave16mct]

That's ok for a 60 duplex frame. The bolts have a head like a coach bolt. They fit in a rubber sleeve and swell this out when tightened. Someone has slotted the ends to prevent them turning while tightening. Try pulling them out. There's a very good illustration in the 1960 manual.
Dave.

[Mick D]

Hi

The rubbers will have become stuck to the tubes in the tank and just pulling on the bolt is not the easiest way to break the bond, get some washing up liquid and pour it around the periphery of the rubber easing it away from the tube with a small screwdriver etc. The bond will break and you will be able to pull the rubber out. Repeat for the second rubber, this time rotating the bolt in circles whilst gently pulling to ease out the rubber.

I think the screwdriver slots in the bolts are by design, well they are in the manual illustration

Regards Mick

[bob121]

I was warned not to reuse the rear mount. As it clamps the rear of the tank to the top tube of the frame. It can and approximately does cause the tank to split. So the rear of my tank sits on a piece of rubber.

[MalcW]

I was warned not to reuse the rear mount. As it clamps the rear of the tank to the top tube of the frame. It can and approximately does cause the tank to split. So the rear of my tank sits on a piece of rubber.

I've not heard that. Mine is loosely bolted down at the rear, with a circular rubber pad under the tank mount, and another plus a large washer under the bolt head. The bolt won't come out as the seat is on top of it. No problems so far.

Malc

[ixonchitts]

Cheers guys, managed to remove them ok with your advice and a look at the 1960 manual makes it clear as you said. All in good order just need to clean up the threads. I only had a copy of the 1959 all models manual from the PO which shows the earlier arrangement - hence my confusion

I think the rear mount is a later addition to my tank - I leave the bolts fairly loose and haven't had a problem - so far!

Thanks again

[Duncan]

I was warned not to reuse the rear mount. As it clamps the rear of the tank to the top tube of the frame. It can and approximately does cause the tank to split. So the rear of my tank sits on a piece of rubber.

There was a 350 single tank (one year only I think) than had a single bolt fixing tang on it at this time this is the one that people say can split the tank, the clamp around the top tube (with rubber padding) is fine.

[Andy G]

Steve, I am trying to identify the correct tank for my 62 duplex framed 31csr. Would you be so kind as to measure the gap at the front of the tank, is it same width top to bottom?

[bob121]

I was warned not to reuse the rear mount. As it clamps the rear of the tank to the top tube of the frame. It can and approximately does cause the tank to split. So the rear of my tank sits on a piece of rubber.

There was a 350 single tank (one year only I think) than had a single bolt fixing tang on it at this time this is the one that people say can split the tank, the clamp around the top tube (with rubber padding) is fine.

That's good to know. I think I'll fish out the clamp and fit it the next service.