Questions, new to Hayabusa's..........

Alright then, older biker. Been riding 20+ years, early on I raced 600 Super Sport for two seasons. Pretty good around bikes, I do all my own work at home, ect. I've owned from a 89 FZR600, a couple others, some Buells, a 98 900RR, and now the 04 Busa. Questions for those who've owned and worked on Hayabusa's, basically those who've experienced these monsters :laugh:

1) In general, is the clutch pretty vague compared to other bikes? Its what I'm finding on mine. Learning it, but mine feels vague.

2) Pure fueling question............... On mine, I have a Yosh full exhaust, a ATRE, airbox mod, PC3 USB running the downloaded correct map. I went for a long ride today after resetting the trip meter. I was very mild with the throttle but only got 27 MPG?!? Is that right? I have noticed some wires tied into the harness at the computer, they are not connected. Is there any easy way to tell if I'm doubling up on the "tuning" with the PC3 and possibly already programmed computer? It runs ok, doesn't overheat, but that mileage really makes me question whats actually going on.

3) At 6 foot tall and 42 years old, I'm seriously leaning toward lifting the bars and dropping the pegs. I keep going back and forth on the bars, either the 3/4 spacer, 1 inch spacer, heli bars, or the 3/4 plus heli's. Just not sure and I hate to spend money twice. The peg drops are between some ebay $40 1 inch drops and some Buells. Any thoughts on them?

And for ****s and giggles, a list of what I've done so far...............
Tossed the shinkos, went Pirelli Angles
90 degree valve stems
Removed the tiger tail, and got back the trunk
Rebuilt/resprung the forks and lifted up to stock height
Removed lowering links
Removed the crappy LED light kit, was glued onto multiple panels- couldn't even change oil?!?
Replaced sprockets and chain
Removed excessive chrome accessories, replaced with stock pieces (no more sunlight in my eyes!!!!)
Replaced brake pads, I'm good with the Galfer brake rotors
Removed the crappy job HID light kits, went with Silverstars (repairing the harness also)
Repaired the tail harness, removed resistors, installed a EP35 flasher
Shaved new undertail, installed custom plate bracket and LED plate light


Welcome! And you might want to look into the LSL handle bar kit for your busa. Heard a lot of taller guys give good reviews on it and how it helped with a more comfortable ride :whistle:
If the PC3 has a map downloaded from dyno jet, those maps run very rich. That combined with an ATRE (which basically runs the 5th gear fuel map no matter what gear you're in will lower your MPG..although, I've never seen it as low as 27. The loose wires connected to the ECU harness may be a connector for an ECU Editor. It's possible that your ECU has been edited to remove restrictions and timing retard in the lower gears. If that's the case then the ATRE is redundant. It's also possible that the ECU was tuned for fuel/ignition as well and if that's the case, the PC3 would override whatever fuel map tuning was done to the ECU.

You may want to remove the ATRE and PC3 and see how the bike runs. Then add back the PC3 and test it again. If it feels like you have less smoothness in the lower gears (around town driving) then send your ECU to Powerhouse and have it edited and ditch the ATRE.
Oh the joys of buying an "unknown" bike. I can't complain too much, got it for $3500
I'll pull the stuff this week and see how she does. I don't need a rocket, just some good strong torque for two up riding with the wife. All else fails, I'll pull the computer and send it in to be done right. I'll hit the garage in a moment and get some pics, including the harness I/we suspect was for tuning the computer.

I've done several street fighter bikes with dirt bike bars, lots of fun and good leverage with my VERY wide shoulders. Just didn't want to go that route with this one. Going to keep the fairings and not stand out near as much as before (not that a black/blue/chrome Busa doesn't stand out). Probably going to start with the 1 inch spacers and see how it feels. I still need to run power ports and mount up my GPS.
Here's the pics.....................
Sorry its raining now and I have a crappy camera. So you gets what you get.

And the suspect harness wires, wonder EXACTLY whats in that programming mmmmmmmmmmmmmm?
They go no where. Basically the electrical tape is covering the splices that use to be there. Every taped off wire splice has a wire that was connected to the harness but was detached by cutting it off at the tape edge. Does it look like the normal area to splice into to do tuning/flashing?

Blanca BusaLess

Suffers from PBSD
Donating Member
I had an xtre on my genII and got 25mpgs. Took it off and now get almost 45mpgs.
And the bike makes same Hp to within 1 as evidenced by before and after DYNO runs I did.
Well, that sucked. Removed the ATRE and the PC3, I went a total of 29.4 miles. Got 30.0 for the first 14.7 and a whopping 34.8 on the trip back. Reset before each leg, 60 to 70 mph steady easy driving, no stops or braking, mild acceleration. Burned more than a 1/4 tank of fuel (closer to 1/2) for the trip. Could it really be tuned that rich? I had a 900RR street fighter with carbs I tuned that got 40 mpg with steady cruising. WTF? Anything else to look for or at before I have an aneurism and ship out the computer?
Keep removing the addons except the exhaust of course...get the bike back to stock, check the state of the spark plugs and air filter.
Then if refitting the PC3 get it properly mapped...downloaded maps are rubbish and should only be used as a starting point for real mapping...never found a good free map for my old Gen1 and eventually removed the PC3 completely..mpg was almost always better without it and for me that was more beneficial than a few hp at 9 or 10k revs.
That's pretty much it. No other visible mods. I decided to let it sit for today as I can't even get parts on sunday. Air filter is clean, I'll replace the plugs this week and start the test over.

Other than the mileage, vague clutch, and lifting the bars, the only other thing bothering me is the lack of low end grunt. Might have everything to do with plugs or computer tune, I'll see later this week. I might have to wait till next week due to a major match I have to be ready for, but it WILL be done before summer gets here!


Seasoned Beef
Donating Member
When I made simple changes to my '06, like changing plugs the bike would take a couple hundred miles to settle out and get back on track.
When I made simple changes to my '06, like changing plugs the bike would take a couple hundred miles to settle out and get back on track.
Maybe, I'll have a little time Tuesday to go hammer it and see if it settles down. I keep thinking older injection styles where you get immediate feed back as the computer doesn't compensate.


Seasoned Beef
Donating Member
The exhaust can give you added flow and lower your fuel mileage. Maybe 45 to 47 is what you would see if all things were good.
Small update....................................
I'm so OCD sometimes, I keep looking for issues on the bike............. found the clutch safety switch wires bypassed!!! DOH! After a little web searching, this might be part of my issues with the bike. Friday morning when I'm off work I'll repair them and see what's what. Hopefully it will be a good thing, and I can then move on to other things/upgrades.

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