regulator ?????

new to this & just picked up a 03 busa in pieces , gettin it put together. came to some vac lines that the disk/manual says goes to the fuel pump regulator, but dont have a regulator on it. I geuss I need to get one ?? any help


Donating Member
on a 2003 the regulator is inside the tank with the fuel pump. There are no vac lines that run to the regualator. The fuel pressure is set at a specific pressure and the only pressure changes would be based on voltage not vacuum. Maybe your manual is for the earlier models that had the external pump?
Thanks yall. yeah your right the manual says 99-03 but the pump is external, not in the tank like mine. So I dont need a regulator, but where does the vacum line that comes out between the center two T-bodies connect to? Looks like it use to go to the bottom of the air box, but the manual says another line goes there, but then again the manual might be wrong again. Also the two vent lines off the back of the tank one large one small any idea where I should connect those or are they just vents? Any help greatly apprieciated.


Lily's Daddy
The small one that goes to the air box ..attaches to the sensor mounted on the back left of the air box...
the larger one on the back of the air box goes to the crancase vent
the one from the vacuum control valve goes to the flapper valve on the underside of the air box right dead center
the others are just vents that go down under the bike...should be a battery drain and one, maybe 2 from the gas tank

thanks, theres another black plastic part under the vac dampener with a line out the bottom ,any geuss where that line would go ?has a wire ran to it also if that helps

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