Diaphragm Assembly (Octopus) Testing and Fuel Hose Routing Diagram

[Mike Hart]

Diaphragm Assembly (Octopus) Testing and Fuel Hose Routing Diagram
from the XS1100SF service manual
Edited by Mike Hart

This diagram is also found under the seat - but not everyone has a stock seat, or an intact diagram, so here is how to route your octopus hoses:


There are two tests for proper function:

1. With the petcock in the ON or RES position (engine not running), gas should not flow from the fuel pipes (A) when they are removed from the petcocks.
2. Then remove the vacuum pipe from the carb and put a vacuum on it (mouth is ok), and fuel should flow.

If either or both of these tests fail, the diaphragm in the octopus could be dirty or bad. Jeremy Sells reports that a vacuum diaphragm from a Standard petcock is the same and can be used as a replacement, and is much less expensive than a rebuild kit.

I hope this has helped. Please Email me with any corrections, suggestions, or comments.