2000 fuel problem


I have a 2000 busa with 7,000 miles on it, 100% bone stock, never modified in any way. It was in storage for the last couple years and when I took it out, it wouldn't start. Battery was bad so I replaced that and continued to have problems getting it to start. Replaced the plugs, drained all fuel out and put fresh fuel in and the only way I could get it the engine to catch was spray some starting fluid into the air box. That would cause it to cough and catch for a second or two. At least that verified that I was getting spark in the cylinders.

Fuel pressure was low so I replaced the fuel pump and fuel filter as well as the fuel lines. I also removed and cleaned the injectors.

Still couldn't get it to start until I disconnected the air pressure sensor vacuum line. At that point, along with a few teaspoons of gas down the throttle bodies I could get the engine to start and run very poorly.

Checking fuel pressure with the new pump, it is only registering 15psi which is clearly too low and will cause the engine to barely run.

I'm sort of out of thoughts on what to look into next. Was hoping someone on this forum might have a suggestion or two.


Sounds like you need to start with a new pump. Only 15psi? Isn't it supposed to be around 20 something? I'd start with a newer pump...and then work my way from there. Have you checked/cleaned out your t-rail? Could be some gunk in there, too. Also be sure to check your gas tank too...some nasty stuff can build up in a gas tank. I know from experience. ???

Welcome to the board. :thumbsup:
Actually, stock fuel pressure is 43 PSI. Aftermarket pump is a tad higher. If the bike sat for a number of years the entire fuel system is suspect. Remove all fuel filters and check tank for rust.

He's correct, 43psi is what it should be. If you have a new pump, it's assumed to be good, put a meter on the connections to make sure you have sufficient voltage. Does it crank slow?

In all my years messing with these bikes, I've never worked on a 99-2000 with an external fuel pump. However I have an engine with a fuel pump out of one sitting in my shop. There's also an external regulator that I'd suspect is gummed up. The regulator has 2 Phillips head screws on it, and has a vacume line connected to it if memory servers me right.

Assuming you have proper voltage, the fuel filter isn't clogged, and your measuring pressure on the line that goes between the pump and rail, I'd be willing to bet it's the regulator.