ST1100 Vacuum Fuel Shutoff Repair sequence help needed

ladder106 said:

If anyone can suggest a place to purchase these for a reasonable price, I'd be obliged.

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ladder106 said:

I've never had mine apart but understand the need for a fuel shut-off to prevent fuel from gravity feeding past the carb float valves and contaminating your engine oil.....making for very expensive repairs.

The ST is fairly new to me and also my first bike with a fuel tank that is not in the conventional (gravity feed) location on the bike. On all my other machines I make CERTAIN that the fuel is OFF when the bike is not in use and have replace any vacuum operated valves with manually operated valved. I realize that this is not an option on the ST due to the placement of the valve (without drilling a big hole in the faux-fuel tank at least)

I don't know how much fuel will actually gravity feed into the ST without the fuel pump running but I'm certain that some part of a full tank will since that's the reason Honda went to the expense of fitting this valve in the first place.

I know that many...well most long-term ST owners have removed this valve but, in my view at least, it should be necessary to provide an additional valve between the fuel tank and the carbs rather than relying on the float valves alone.

WHEW !....Now to try to answer your question.

The general way these valves work is for the spring to holed the valve CLOSED so fuel can not flow.

Then when the engine starts, manifold vacuum acts on the diaphragm to OPEN the valve and allow fuel to flow.

Either by studying the valve or by attaching a few bits of tubing and simply sucking and/or blowing through the lines you should find the combination that allows the valve to work as intended.

Hope this helps, let us know.

Ray

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