Been having problems on longer rides 5-8 hourson the '99 (rarely noticed it on local runs). Has Power Commander with Custom map(from sniffer dyno apparently tuned to bike) Full RS3 Yosh Carbon/Stainless Pipe, BMC Filter (clean/oiled)Muzzy Fan..and 22,000 Miles. The problem. Cruising at about 80mph/4200RPM if I spike to 90mph or so then decelerate bike engine cuts out. Sometimes I can downshift and get it back, or hold in clutch to try restarting. A few occasions I had to pull over to restart. The problem is highly unpredictable and happened at lower speeds but mainly after steady 80mph cruise. Throttle set/ idle set, bodies synced, valves checked (wouldn't be that anyway) Completely disassembled and cleaned fuel system (original pump and screen replaced because of all the copper junk clogging filters typical 99 problem ) just in case since that was my first guess, No FI light anytime+no stored errors of any kind. Very frustrating problem...seems to be a higher milage Busa problem, any serious help or suggestions appreciated. Thanks guys, will be tearing thing apart this weekend to try and figure something out or she's gonna have to be replaced I can't take it on longer rides anymore.
1999 busa problem
- Thread starter gixerman
- Start date
Maybe an older Busa problem, but 22,000 isn't high milage. I'll have that on my 05 by the end of the month. It sounds like a fuel/air problem. How are your vacuum lines?
homernukem
Registered
My 99 busa does it too if I have to stop or slow down suddenly. Since I already have the clutch pulled in I just shift down once or twice then let out the clutch. But I've ridden dirtbikes for years and I'm not afraid to push start my bike. I was wondering if it wasn't a clutch thing causing it.
IG.
Registered
Before you tear apart... Let me ask you - did it start happening suddenly, or gradually - I mean once a year, then once in a few months, then once a month, etc.?
I had something similar with my '01. The engine would cut out for a moment, or even shut down on me pretty randomly. In retrospect, it started from about once a year, then once in a few months, and so on, until it became a real problem. Long story short, it turned out to be a bad connection somewhere in one of the connectors due to oxidation or dirt or who knows why. What happens is that at a certain rpm of the engine may cause the connector to resonate and momentarily break a poor connection, and the engine either dies or stumbles. That's why it happens consistently in similar scenarios. And, that's why ECU doesn't throw any codes - e.g. if the ECU loses power for a moment, it doesn't know that. However, if a bad connection is somewhere where ECU can detect, it can throw a code. If it doesn't happen on the bumps only, I would rule out the kickstand switch.
So, before tearing the thing apart, all you gotta do is to get an electric contact cleaner (a spray can which you shoot at the connector - just follow instructions, Home Depot has it), and a tube of dialectric grease from any auto parts store. Then all you gotta do is to disconnect all connectors on your bike, one at a time, specifically from/to ECU, power commander, a bunch of connectors under the tank, spark plug connectors, etc. Clean with the contact cleaner per instructions (which is pretty much spray in there, let it drip and dry), and then put the dialectric grease on the connectors - both male and female, and close it back. Dialectric grease has special properties - it gets easily squeezed by the connectors pressed against each other and thus does not obstruct a good contact, while at the same time covering metal surface and keeping bad elements away.
While you open every connector, take a peak with a good flashlight if you see any really corroded connectors, or another bad possibility is that somehow greasy stuff/dirt/oil could get into a connector. I had an oily looking stuff inside one connector under the tank, and for the life of me couldn't figure out how this stuff got in there.
While at it, see if you notice anything abnormal - like bent or pinched cables.
If you doubt a kickstand switch, unplug the connector and replace it with a clip or something which would short the pins reliably.
But do one thing at a time, otherwise you wouldn't know where the problem was. Let's say if you suspect a kickstand switch, disconnect it, short and ride like that until you are positive the problem went away. If it didn't, then move to the next possibility - clean/lube all connectors. Or, the othe way around.
I had something similar with my '01. The engine would cut out for a moment, or even shut down on me pretty randomly. In retrospect, it started from about once a year, then once in a few months, and so on, until it became a real problem. Long story short, it turned out to be a bad connection somewhere in one of the connectors due to oxidation or dirt or who knows why. What happens is that at a certain rpm of the engine may cause the connector to resonate and momentarily break a poor connection, and the engine either dies or stumbles. That's why it happens consistently in similar scenarios. And, that's why ECU doesn't throw any codes - e.g. if the ECU loses power for a moment, it doesn't know that. However, if a bad connection is somewhere where ECU can detect, it can throw a code. If it doesn't happen on the bumps only, I would rule out the kickstand switch.
So, before tearing the thing apart, all you gotta do is to get an electric contact cleaner (a spray can which you shoot at the connector - just follow instructions, Home Depot has it), and a tube of dialectric grease from any auto parts store. Then all you gotta do is to disconnect all connectors on your bike, one at a time, specifically from/to ECU, power commander, a bunch of connectors under the tank, spark plug connectors, etc. Clean with the contact cleaner per instructions (which is pretty much spray in there, let it drip and dry), and then put the dialectric grease on the connectors - both male and female, and close it back. Dialectric grease has special properties - it gets easily squeezed by the connectors pressed against each other and thus does not obstruct a good contact, while at the same time covering metal surface and keeping bad elements away.
While you open every connector, take a peak with a good flashlight if you see any really corroded connectors, or another bad possibility is that somehow greasy stuff/dirt/oil could get into a connector. I had an oily looking stuff inside one connector under the tank, and for the life of me couldn't figure out how this stuff got in there.
While at it, see if you notice anything abnormal - like bent or pinched cables.
If you doubt a kickstand switch, unplug the connector and replace it with a clip or something which would short the pins reliably.
But do one thing at a time, otherwise you wouldn't know where the problem was. Let's say if you suspect a kickstand switch, disconnect it, short and ride like that until you are positive the problem went away. If it didn't, then move to the next possibility - clean/lube all connectors. Or, the othe way around.
CopMagnet5oh
Registered
is your fuel pump properly heat insulated ? stock foam is usually gone after the first fuel filter change, once it gets hot the fuel may get too hot because of the external fuel pump on our '99s. u may need to get good wrap and wrap that pump under the tank.
my .02
- Konstantin
my .02
- Konstantin
CopMagnet5oh
Registered
wheres the second screen ? theres this thing and i've changed the filter, but i didnt see any other screens ...
jdsbusa
Registered
wheres the second screen ? theres this thing and i've changed the filter, but i didnt see any other screens ...
Have you torn apart the tank? A member recently did his and had a boatload of what you've just pictured sitting in the bottom of the bowl where the pump is inside the tank - it was rustastic!
CopMagnet5oh
Registered
its a 99 busa we're talking about here ... 
fuel pump is not inside the tank.
fuel pump is not inside the tank.
Last edited:
CopMagnet5oh
Registered
Ronayers.com Fiche Desktop Motorcycle Suzuki 2000 GSX1300R HAYABUSA PUMP ASSY (MODEL X/Y)
show me which screens need to be cleaned ?
thanks dude !
CopMagnet5oh
Registered
done . awesome !
somehow i lost the O ring that goes on the pump neck ... dammit
. awesome !somehow i lost the O ring that goes on the pump neck ... dammit
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