Hayabusa 2000 stuttering in low revs

hpridal

Registered
Hello guys, I have spent several hours searching for solution of my problem but I ran out of ideas, maybe somebody solved already the same issue. My Hayabusa is year 2000, 40,000km, everything stock. One morning after cold start it seemed like going on 3 cylinders, after approx half minute everything got back to normal. I thought about faulty sparkplug. On the way home (200km) I felt on the highway low power and when I slowed down and accelerated at low speeds the engine was stuttering like hell, I nearly did not get home. What is strange when reaching 7,000 revs it runs like hell with full power. I already tried:

- changing sparkplugs
- changing gasoline for Shell 100oct
- checked fuel tubes
- checked air temp sensor
- fuel pump I have no measurement but I assume that if it would be faulty, it would not give enough gasoline in the high revs and not in the low revs
- checked compression, I have 9,5-10 on all cylinders
- turned the throttle sensor (on the left side), in one position I even did not get the bike from the idle, another position was quite better but still by giving full throttle it stutters
- error code C00...

When I start engine without airbox and get in revs, I can see little flames comming out of the throttle valves..

the bike had always full service, approx one year ago were clogged injectors and cleaned, since this running without any problem. What do you think could be this thing? My assumptions are that if fuel system is faulty, it would not run in high revs (from not having enough fuel), and if the engine would be gone it would maybe make some noise of give warning before? I dont want to believe that engine dies so suddenly without any previous symtoms..

thanks for ideas, I get desperate...
 
Its a clogged fuel pump screen, and possibly fuel pump as well. The 1999 and 2000 had a poor design for the fuel pump set-up, and they usually seem to start giving problems at about your mileage. The fact you already had plugged injectors points to that even more. Clean the screen and check the pump :thumbsup:
 
Thanks for reply, I will give it a try tomorrow with another fuel pump from a car, I will see if something changes. Now the injectors are cleaned from ultrasound, the bike goes normally in revs but at the cold engine it is hell noisy, when warm it calms down a bit. I am really really affraid that the engine is gone :( Lets wait for tomorrow, I will post here the result.
 
When you turn the key without starting, do you hear a whine for a cpl of seconds? if yes, then it's your fuel pump working. Could be one of your your ignition coils going bad, just a thought.
 
So, yesterday I spent whole day on research of my problem. As you guys told me I checked fuel pump. The filter was quite dirty, so I disassembled everything and cleaned properly, new filter comes this week. And now the story:
After cleaning I went for test drive, approx 2 km was the same problem and then suddenly disappeared and was running like hell! I was so happy, but after next 5km the problem appeared again. I thought the pump is gone, so I connected a fuel pump from Suzuki Swift, just a pump in the gasoline and direct pipe in injectors on Busa. The problem immediately disappeared and the bike went smoothly in revs. Fine, so I fitted it in the alluminium case and started. And again everything wrong. Further testing was that I took the original pump from Busa, give it in the gasoline and connected directly in injectors. And everything runs! Looks like the pump works fine. But as I give it in the alu case I am in the same crap :(( This led me to assumptions that maybe the fuel filter is so clogged, so I removed it to try. Same problem. I really do not know what to do further. If I just give the fuel pump in the gasoline and connect directly to the bike, everything works, but as soon as I give it in the case, sucks.. It is not the electric problem, I tried both connecting directly on battery and original connector, it does the same result. All holes are cleaned properly and there is no dirt anywhere. Any ideas? Here is a video what my bike does (+ has significantly less power)

[video]https://picasaweb.google.com/hpridal/Hayabusa#5744159495234731938[/video]

and photo what came out of the fuel filter:
IMAGE_7EF97C04-2677-42C5-9830-76DCF440148E.JPG
 
So the latest news the problem appears always, even without the ALU cover :( Have to find somebody else to work on it, I got empty with ideas..
 
GoldenChild: Europe, Czech republic

So today i moved forward, we checked the fuel pump on the pressure meter and on startup does a good pressure, but then gets lower. I ordered new in Suzuki (300 EUR hurts..), the aftermarket would have to be from US and with customs office here and all the stuff I would be waiting 3 weeks and season is short here :( So hopefully it will solve the problem, I will let you know..
 
My bike does the same thing. It doesnt run smooth in low gears. Only time it runs smooth is in 5th and 6th gear. Its as if the bike is jumping gears on me, as if someone is pushing and tugging me when I am in low gear. Lets say I go in a school zone, its famous for doing it there. lol No ideas either.
 
I had the same problem with mine the other day. I took it to the local shop when they had a dyno day and found out the bike was lean. Made 122 hp is was that lean. Since then I added the ecu editor and have been tuning on the street. My stumble was from it being lean down low. I have added almost 20% fuel to it to get it smooth. afr is around 13.8-14. the bike has the airbox mod and a homemade 4-2-1 using stock header and yosh slip-on.
 
Hello, it still sucks, but I have the same problem even after changing the fuel pump. So after spending 2 weekends and many sleepless nights I will drive it to Suzuki next week. I am really done with this bike..
 
Hey guys, I found it! So as I wrote, changed fuel pump, fuel filter, chleaned everything and also had the injectors on ultrasound cleaning. I gave in the new pump and the bike didnt wanted to go from idle. I was desperate, but took out injectors and sprayed them with cleaner. Afterwards it went in the revs, but on test drive the performance was quite poor and after approx 3 kilometers the bike stopped and didnt want to go from idle and was dying. Again, after spraying in the injectors was good for exactly 3kms. You cannot believe how pissed off I was calling my friend to pick me up with a Transporter.. I left the injectors in the cleaner overnight, did not help. Then I spent one more evening with browsing and found out that on the older models are also little screens in the injectors. I took them out (one was completely rusty) - and HALLELUJAH! It runs again with full power. So if somebody will solve a similar problem, I strongly recommend to check this at first, to get them out takes 5-10minutes.. I am happy opening my victory beer now. Thanks to all for advices
 
I had the same problem with mine the other day. I took it to the local shop when they had a dyno day and found out the bike was lean. Made 122 hp is was that lean. Since then I added the ecu editor and have been tuning on the street. My stumble was from it being lean down low. I have added almost 20% fuel to it to get it smooth. afr is around 13.8-14. the bike has the airbox mod and a homemade 4-2-1 using stock header and yosh slip-on.

my bike has a similar stumble/chug at low rpms (below 2500 or so) and I believe its being caused by this same thing, as I haven't been able to get a really good PC map for my exhaust setup...
 
Old old thread, my '00 had same exact problem. Was in middle of 1000 mile weekend, and it barely ran.

It would run as long as the tank was full, below 1/2 full, fuel starvation problem returned. (figure that out)

Disassembled and rebuilt the fuel filter / pump (huge pain! on the '00) and all good again.

Filter was disintegrating inside the fuel pump. Nasty.
 
Hi
Does anybody have some pics on how you remove the screens on the injectors?

I did the fuel pump upgrade and changed the filters in the fuel pump and now it runs great but i didn't clean the screens in the injectors...

Best Regards
 
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