Gas Cap ID

[bull gear]

I picked up a tank but can't figure out what gas cap I need.
The tank has the attributes of an early Special tank... offset cap and dual petcocks with the "odd" bolt pattern.
The cap from the MikeXS tank won't fit (but the petcocks will), nor will the replacement Emgo "special" that I bought, which appears to be the same as the MikesXS. The mount hole to lock pin spacing on those is too short.
HELP!!! What cap do I need!?

 

[gggGary]

A shot of the bottom of the tank may reveal if it is XS650, or maybe something else.

 

[5twins]

If you provide the measurement from the mount hole to the latch pin, maybe someone can figure out if what they have is what you need.

 

[bull gear]

Never occured to me that it could be something else. Seems to fit perfectly. Mount hole to pin = 78mm (3-3/32"). Thanks.

 

[fredintoon]

Never occured to me that it could be something else. Seems to fit perfectly. Mount hole to pin = 78mm (3-3/32"). Thanks.

Hi bull gear,
Did you check that tank's capacity vs the Special's 11.5 liters?
Here's what I measured on my bikes:-
Pin center to mount hole center of Standard tank, 72.4mm (~ 2-7/8")
Pin center to mount hole center of Special tank, 76.2 mm (~ 3")
Are you certain sure about your tank's cap mounting dimension?
FYI the Late model (key in the top) Standard tank caps and the Special tank caps LOOK the same but they DON'T swap.
OTOH, the filler caps on XS11 Specials and XS650 Specials DO swap.
And if all else fails, move the latch pin, it's only 3/32", eh?

 

[5twins]

I checked the original tank on my Standard, it's a little over 72mm. A junk newer Special Tank (one petcock) I have measures a little over 78mm. It appears the caps you have are for the Standard tank. Mike's sells a different one for the Special tank, no doubt longer. But I bet Gary can set you up with a nice used one.

 

[bull gear]

Well then... I'm starting to think that this Emgo cap, part #43-61020, which is supposed to be a "Special" cap, is actually for a "Standard". Imagine that... a Taiwan part that doesn't fit!!!
Anybody have a good "Special" cap for me?

 

[gggGary]

should have, later.

 

[gggGary]

I have special caps with and without keys. would take a "new" standard cap as trade....