fuel line conections and routing

so i picked up what im hoping to be a quick fixer upper bikes fuel lines and tank were off the bike when i got it now ive cleaned carbs cleaned tank rebuilt pet cocks and im dying to try and fire it but it has this lil thing on it like a vacume diaphram? located on top of the cabs. help me figure this out guys ???? thank you in advance this is a grerat place for info.
82 MAXIM ELEVEN HUNDRED

 

That is the fuel distribution "octopus" and iallows the "automatic" on/off function of the petcocks (using engine vacuum, which is present when the engine is cranking or running, and of course is absent when the engine is off). In a nutshell, it works like this:

- when engine vacuum is created, this vacuum signal (via a hose running from one of the 4 intake manifolds to this octopus) pulls open a spring-loaded diaphram which is connected to a plunger that either seals off, or, when vacuum is present, pulls this plunger out of the fuel flow passageway and allows fuel to flow.

- the "fuel passageway" is from the petcock outlet, to the octopus, and then---if vacuum is present and the passageway is thus opened---fuel flows back out of the octopus and onto the carbs.

Note that on XS/XJ1100 engines, there are 2 petcocks, and each petcock feeds two carbs. Thus on the octopus there are two fuel inlets (one from each petcock), and two fuel outlets (one to the #1/2 carbs fuel inlet t-fitting, and another to the #3/4 carbs fuel inlet t-fitting).

Also note that the vacuum, from the engine, does not "pull" the fuel out of the tank; the fuel flow is completely dependent on gravity, and whether the on/off plunger within the octopus has been pulled open by engine vacuum or not.

This is how all automatic petcocks work, even on the smaller engines...........on those petcocks, the vacuum diaphram/plunger is built into the back of the petcock body itself; it's only on some of the 1100's where the vacuum module has been located remotely from the petcock body.

 

thank you thats great info if only i had i pic of how its set up

 

There is a drawing of the fuel line routing on a decal that is affixed under the seat pan.