Carburetors on a '78 Standard

[oldsbastel]

Does anybody now the exact type of carburetors, which where used on a '78 Standard in America?

I need to know, if Yamaha used different carburators on a German (2H9) and an American (2H7) XS 1100.

The German carburetor type is BS34-II-2H9-00

[sidecarKev]

The German version seems to be the same as the UK version.
The US # is Mikuni BS34-II 2H7-00.

Info found at
Motorcycle Carbs

[oldsbastel]

Hmmm, but what is the difference between ....2H7... and .... 2H9...? Only the main jets (132,5 (2H9) vs. 137,5 (2H7) )?

Has anybody got a parts list for a Mikuni BS34-II 2H7-00 or is there a parts list available on the web?

[sidecarKev]

I remembered seeing a UK XS1100 site. Here is a page from there on UK carb specs.
UK Carb Specs

US Specs are here.
US Specs

[oldsbastel]

I'm still wondering, why they used different jets in America and Europe. It's the same engine.

Does anybody know more about that?

[sidecarKev]

Maybe you can find out why there is a difference on one of these German XS1100 sites. But I would guess that a US version of the carb would bolt right on and work. Maybe at the time they had to tune it different for regulations or emissions or something. Lots of bikes besides the XS1100 had different things changed on them for who knows what reasons when they went to different countries.

http://www.xs1100.org
http://www.xs1100.de