Gas Tank Shape

[littlebill31]

I've been looking for a more squared off gas tank to put on my '81H.
So it got me thinking.
Through the years, what tanks have the most squared'ness and would they fit on an '81.
The XS750 and GS450 are my favorite, but the prices have shot up and, of course, the modifications needed.

 

[angus67]

The xs1100 tank looks good.

 

[fredintoon]

The xs1100 tank looks good.

Hi angus,
yeah, both the Standard and the Special XS11 tanks look good and have more capacity than an XS650 tank but to me neither of them look particularly squared off.
And more importantly, the XS11 frame's twin top tubes means the XS11 tank tunnels have to be as wide as the grand canyon which'll make them a bitch to fit on an XS650.
OTOH, although an XS650 STANDARD tank don't look to be particularly squared off neither it will drop straight onto an '81 with no mods at all AND it holds an extra gallon of gas.

 

[littlebill31]

Thanks Angus and Fred,
I like the Standard idea. I just want a little more box to my tank. Not as tapered.

 

[littlebill31]

So here is another question.
Can older tanks, like a '72, work on a single petcock '81?
Meaning, if I filled one of the duals on the older tank of course.
Not sure if those tanks allow gas from either side to freely move in the tank. Or would you have a lot of gas on the non petcock side as the level dropped.

 

[650Skull]

I have heard of people using the early 70-73 tanks on the Standard and Specials but they are shorter in length and don't reach the rear hod down bolt.
petcocks; It would be as simple as running from both petcocks to a T or Y then into the BS 34's.

XS1/1B/XS2 Same tank.


73TX650 tank is a slightly different shape from the 70-72 Tanks. Gas cap the same as 74TXA/75XSB



Here are some pics of the different standard Tanks on the 74-79 Standards.

74TXA-75XSB. Gas cap is obsolete, (no aftermarket replacement), so make sure the cap comes with all working parts in good order. This cap was also on the 73TX650, 73/74TX750, 73-75TX/XS500. 73-75RD250/350.
Tank has decals so no mounts for badges.


76C and 77D 76C/77D gas cap can be bought as an aftermarket product. Gas cap from 76C-79F interchange. Tank has decals so no mounts for badges.
NOTE: 76C-79F Tank gas cap can be confused with the Special Gas cap. Standard 76-79 Gas caps do not interchange with Special tank gas caps
76C..............................................................................................77D
Petcocks interchange from 74TXA-77D

78E-79F. Tank Gas cap interchanges with 76C/77D.
NOTE: Tanks have badges. New Badges can cost from $50.00 each Diablo Cycles
NOTE: Petcocks are Vacuum operated and do not interchange with earlier 74-77 Tanks.
78E................................................79F

 

[littlebill31]

Nice!! Great info!!!

That 79 F with the center gas cap really looks nice.

 

[650Skull]

No Prob, just to throw a spanner in the works........................

Over here and in the UK the Standard XS750 triple and XS850 triple had different sized tanks. The XS750 held 17 liters and the XS850 22 liters, The 850 Tank is the same as the Standard XS1100 tank . A guy over here has removed the tunnel off an XS750 and swapped in n XS650 tunnel. Increased the tank capacity from 17 liters to 22 liters.

Comparison of the Non US XS750/XS850 Tanks. The Red and grey non US XS750 Tank is the same as the US XS750/XS850 Tank


This is a pic of a US XS850 Tank.
US XS850 Tunnel, (below), NOTE. The front mount is the opposite to the XS650 mount Meaning the tank has the cups where the XS650 Frame has the cups. Tis an easy fix. The rear tab is bent up so it needs to be straightened and then the tank is basically a bolt on.

 

[fredintoon]

Thanks Angus and Fred,
I like the Standard idea. I just want a little more box to my tank. Not as tapered.

Hi littlebill,
check out NWWA's "Square tank for sale" ad in the classifieds. He's just bumped the ad, perhaps he'd want to dicker on the price, eh?