I'm putting a 2002 Supersport back together and found that the return port on the tank has been blanked off.
I know enough from bike ownership that return lines are only strictly needed for fuel injected engines but the part catalog shows a return line coming off a T-junction after the fuel pump:
So the question is, can I run it properly with it blanked off? (previous owner clearly was)
If I should have a return line, the diagram doesn't show how the fuel doesn't simply circulate directly back into the tank.
I'm guessing there's a check valve inline but those are typically one way and not pressure regulated. Any one have any ideas?
Radicalonline sells a check valve but I have no idea where it would go in a carb setup:
https://www.radicalonline.co.uk/products/FD0004-%252d-Fuel-Check-Valve.html
As you say the return should only be used on fuel injection and then not always required.
if you are on carbs you need a single, pressure regulated, feed to them. This is normally a Facet pump with a low pressure regulator. You should be aiming for around 3 psi. Return isn't required as the float bowls can overcome that pressure and stop supply into the carbs when in the correct position.
The check valve you mention is completely separate and used on the tank breather. This is to allow air in when fuel is used up but stops fuel coming out should the car end up upside down.
Thank you!
I have a Facet pump and it's pushing out about 3 psi so all good on that front.
Good to know on the check valve, I'll have to see if mine has one installed.
The setup in the drawing is significantly different than what i found in my 2003 SR3 Supersport. My car has 2 Facet pumps.
