Just bought an auxiliary fuel tank to tune my motorcycle. The petcock is "gravity" operated. How do I use it?

Question

Perhaps a silly question, but my main question is about vacuum. On a four barrel carburetor for my 1989 Ninja 750R, there are four inlet holes for vacuum. One of them is plugged, stock. Two go to the engine (are split into a V) and one to the fuel petcock. Do I hook up the vacuum hoses normally? Since this tank is gravity, not vacuum operated (no fitting on the petcock for vacuum), what do I do with the inlet that would normally be for that, plug it? Thanks.

Thanks. But the two that go to my engine (going to one and four on the carb) need to be put in place, correct? Just plug the one that normally goes to the petcock?

Answer 1

Not a silly question at all.
Silly is when folks who are uncertain Don't ask.
And then connect Fuel to the vac line,,or leave the vac line open.
The results are Not silly at all.

As to your question,,,Your thinking is Correct.

All that your auxiliary tank has changed is the requirement for a vacuum source.

So merely PLUG the existing Vacuum line when using your TunerTank.

Simple and done.

I'll match you silly for silly with this silly reminder:
*Don't Forget to re-connect the Vacuum line to the Original Tank.
*Don't Ever connect Fuel Outlet to the Vacuum Line.

*Make certain that your "Hose Plug" for that Vac Hose.......
a)Seals Completely--No Vacuum Leak
b)Wont get sucked down into the hose

Good Luck!

** One other thing,,,just for the sake of saying.
This may or may not apply in your case.
Auxilliary Tanks CAN be rather fragile.
They might get punctured or split ,,,,
or Cap may break or pop off if tank happens to get dropped.
Or if something 'round the shop falls into it.

Odds of such an occurrence are probly in the millions.
Over the years I've seen it happen several times,,and seen quite a few leaks & spills.
RARE,,but it happens.

So,,Just a friendly reminder of the obvious--BE CAREFUL

Answer 2

The easy way: Turn Petcock to OFF. Make sure all your hoses are connected normally. Remove fuel line from petcock and connect to new tank valve. Splice in a piece or use a longer hose to reach the normal fuel inlet on the fuel rail. Don't worry about the vacuum lines, they will just do what they normally do.

Answer 3

all you need to do is plug any extra vacuum lies and raise the auxiliary fuel tank higher than your carbs.