Hayabusa Fuel Pump


Hi there!
I have a Hayabusa 1999 model, which gives me problems: sometimes engine stops at traffic lights (only after warming up period) , it doesn't go up more than 7000 rpm , hesitations.
I have read a lot of threads on this website , and it looks like the problem is common , but still no satisfaction on my case
I have replaced: ECU , SparkPlugs, Charging Regulator.
I have tested : fuel pump delivery pressure , the fuel regulator, all the vacuum lines.
I have tuned the position and opening of the flaps from each body , checked air filter....
I have even changed the position of the IAT sensor from the air filter case to one of the intake airducts.
I am thinking now to change the fuel pump although the tests were fine.
Any one have come accross anything like this? any different sugestions?
Can I fit a 2004 Hayabusa fuel pump on an 1999 model ,i know they are different, but can it be modified?
Thank You in advance!


Donating Member
04 fuel pump is an intank pump while the 99 is an external pump. The bottom of your 99 tank wont accept an in-tank fuel pump. You can always go with an external bosch or Walbro fuel pump.

What kind of a test did you do with the pump to determine it's good? Did you test the entire fuel system?


I have checked the injectors , they look ok.
I have checked the whole pump assy, all the filters , presure regulator , etc
At the pump i have checked the pressure by the manual.
And now to tell you a good one : I have put by mistake diesel instead of petrol (actually it was the mistake of the Petrol Station). I went like that without knowing , engine stoped and after a while i managed to understand what actually happened. After cleaning the whole fuel system, draining the diesel out , fuel tank and fuel ramp, it works much better no more stoping , still some kind of hesitation...I got to run it for couple more days to see what's going on.
Anyway it's not solved completely yet....


1 wheel up aero testing
Donating Member
I have seen that happen before...it did not do permanent damage on the bike I helped clean out. The gas station had the diesel pumping out of the incorrect pump (per that rider anyway) and he filled his bike up with 40 octane. After we figured out his fuel was green and what had happened (5 hours after the bike stopped runing) we cleaned everything out and it takes a few miles to clear the oily residue out. Run some cleaner and/or some sea foam through it for a few tanks and put a quite a few (fairly easy) miles on it. Hopefully that will help if every thing else checked out ok. (I believe the injectors were the last thing that needed clearing out good on his bike).


boosted finally
Donating Member
you cant tell the injectors are good just by looking at them, try some good injector cleaner, also are you getting the fi light coming on by chance


Fuel lines are the worst on these bikes. Ask me how I know. If you have not upgraded your lines you may want to. You can't really test the lines as they will only slow or stop fuel when the tank is closed.


The injectors were checked properly , the spray pattern the small filters at the top of the injectors. All of them were spraying ok.
The fuel lines were ok as well , dont know if affected when fuel tank closed.
I will double checked...
No trouble codes are present in the ECU (no FI light).


If i will fit an external fuel pump(Bosch , Walbro) what shall i do with the fuel pressure regulator? (Commuta _Busa)


But the regulator is fited on the pump assy.
If i put a new pump (external) how i will connect it with the regulator????


Donating Member
Fuel lines are the worst on these bikes. Ask me how I know. If you have not upgraded your lines you may want to. You can't really test the lines as they will only slow or stop fuel when the tank is closed.
replace lines with some hp hose,just had a bike run great till it warmed up then would lean out eveytime at 6500 rpm,pulled lines and heat was making them collapse,as long as it stayed cool in shop it never went lean...gotta love free air dyno runs,solves problems in itself...


you cant tell the injectors are good just by looking at them, try some good injector cleaner, also are you getting the fi light coming on by chance
izit still ok to ride if FI light comes on ??
had mine on a couple of times, but disappear soon after i re-start the bike...
shud i checked anything ??


Did you ever get this sorted, I have the same fault.

I have checked the pump off the bike, the pressure regulator, changed the lines, checked the Pump Relay and kicked it a few times.


Might, just might, have to take it to a garage.

Runs for about 10 mins and then stops, if you lift the tank it runs a treat. I am thinking the pump but it is fine when it is cold.



Sounds like your lines are kinking under there when the tank is closed. If it runs great with tank up. Try rerouting everything, and finding some wire that surrounds the lines so that they can't kink on the bends. (like the stock ones, but stronger)

Other than that, you might check or replace the battery. The injectors rely on a good battery or else you can possibly get some hesitation and jerking. Usually won't just shut off though...

Sounds like a kink or a clog. I'd also replace the fuel filter and clean out the inside of yours. (replace with inline, search for procedure)


I have chopped and changed the fuel lines, I agree I did have a kink.
I have stripped the fuel pump a couple of times and the last time I thought I may have cracked it when I found a split o-ring, replaced it and guess what.... Nope!

I like the idea of changing the fuel lines to stronger ones though in case the ones I have replaced are collapsing.

With the fuel pump out I checked the filter and blew it out, it felt clear. I have also stripped the tank and checked the strainer/filter inside. No joy.

I even took the tank OFF and ran the bike from an external fuel can (after priming the pump), it still stopped after about 10 minutes.

There are no error messages on the diagnostics, I am now thinking there could be another sensor fault that I cannot find or that the fuel pump bearings or pressure regulator are gone. Wish I had a spare pump to try it with, of course any old thing with a FPR would be fine!

Sigh... Poor beasty.


What's your temperature like when it dies? Could be a sensor like you're saying, or the themostat. Maybe you're overheating? 10mins of idle used to send my bike to the red zone before I swapped the coolant with water wetter. That's probably not your problem though.

Sounds like once you're up to temp, the bike dies, so I'd look at electrical options next.

UNLESS you really think it is fuel related, and the only thing I can think of there is that once the motor is hot, it's heating up your fuel pump and causing it to fail. If I still had my extra pump I'd let you have it but I gave it away long ago. If you search my name, you can find a walkthrough were I installed all aftermarket fuel stuff on a 99. (pump, reg, filter, etc) but I'd make 100% sure it's the pump before spending the $300+.


Hey there folks - been reading this thread with great interest as I'm experiencing similar issues with my '99 Busa...

Mine was off the road for about 6 years after being run off the road by a little muppet car driver/thief who did a runner as soon as he saw me hit the deck...:banghead:

I won't go into the long, boring story, but this year I finally had the chance to get her back on the road, and with the massive assistance of a young mechanic I know, replacement parts were sourced off Ebay and my Busa grumbled back into life.

I hadn't planned on having her off the road for so long, so didn't prep her for the hibernation, sadly... End result - battery and alarm dead, fuel was off, tank was rusting inside, and the fuel pump was seemingly dead as well (C41 on the FI). Got another battery on her, and my mate stripped out the old alarm which refused to function now... We replaced the fuel pump with one I'd seen on Ebay and after a fresh tank of fuel, cleaning of injectors etc. new oil and plugs, she fired up fairly sweetly with no FI warnings flashing up. Two days later, my mate calls me up to tell me the oil cooler's knackered and has spat the contents down his driveway. Ebay to the rescue again.

After this last hurdle (we thought) the bike was running much, much better, so I took it for a little test run around the block and it would run ok for a bit, then bog down, as if the fuel wasn't flowing properly... After much reading about the pros and cons of de-rusting a fuel tank, thinking this was the problem, I opted for a clean replacement tank off Ebay. This was a massive improvement, but still bogging down under revs. My mate spent another day cleaning and replacing fuel lines, injectors etc. - adjusting and readjusting the TPS, even the breathers from the tank, which I knew from previous bikes could cause problems.

Booked it in for MOT, picked it up from my mate's and got a tank of fuel in her before heading to the MOT place. She bogged down on the way there, after a good 5 or 6 miles of running about for fuel etc. and then refused to start. Phone call to the bike shop and he came to recover the bike. Chap in the shop had worked on a few Busa's apparently, which cheered me up so I left it with him.

When I picked the bike up from its MOT it promptly broke down again (same fuelling problem) about 100yds away and I had to push it back to the guy's shop. He reckoned it was the fuel pump (yes - the replacement one!), so he had the bike back in to strip the pump down and take it from there.

A few days later, the bike was ready so I went to collect it and paid my bill - OUCH!

100yds down the road, it conked out again. Pushed it back. Not happy. Left it with him again...

Phone call - "it's a fuel line under the tank that's kinking - I've replaced it with the right hose - all sorted, mate..."

Picked it up, 100yds again and nothing.

He now reckons, after a couple of months of tinkering with this and that, that the fuel pump is 100% ok, but the battery's on the way out and there could also be a problem with the CDI, which is causing the bogging down under revs - she'll sit there happily ticking over, but the minute you put some load on her, she bogs down and dies again...

Lucid - your suggestions about the electrics sound spot on... If the fuelling appears ok, then it has to be electrical.

If it IS the CDI, the guy in the shop reckons he can get a replacement quite cheap, but he's got a new battery as well, and he's got another Busa coming in in a week or so, so he can swap the CDI with a known working unit and see if that cures it before shelling out on a replacement unit...

I'll keep checking on here to see if the OP, jordinion, had any success fault finding the problem, and if Chris_IPTE has any joy as well with his...

A guy at work suggested that I just break the bike for parts and try and get some money back, but it would break my heart getting so close to having her running again - and with the one brief ride I had on her, I know there can't be much left to sort out...

Fingers crossed for us all...


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