02 Hayabusa Loss Of Power When Warm

Jake Boucher

Registered
2 days ago my bike was knocked over in a parking lot, frame slider and bar ends saved her for the most part. Up until then she has been running great. I bypassed the high pressure filter in the tank and used an inline filter, and that brought my midrange and top end back to life. She was only on her side for 30 seconds or less, I ran my 160 pounds over their and lifted her fat self back upright. She runs great until I've been riding her for a while and she's warm. At first she was loose power and be a bit jerky, now she's smooth but gutless. I checked the tip over switch, no problems there. Pulled the plugs, and they looked lean if anything. No oil where it shouldn't be. I'm just confused because it's heat related. I considered vapor lock, but it only just started doing it and I did the filter bypass weeks ago. I'm going to tighten my throttle body clamps, and double check my vacuum lines right now. I'm having a feeling that problems after the tip over are just a coincidence. Anything I'm overlooking? Tank vent lines are good too.
 
Yes it was idling. It starts up every time without an issue, but after ten minutes or so of riding, I'll gas it from a stop and she's gutless. She still goes all the way through the rpm band, just doesn't have power like she should.
 
Hope it's not the case here but, if oil leaks into the cylinders while it is running or is stared without letting the oil drain out bad things can happen since oil doesn't compress. I would be surprised since bikes go down all the time without having an issue. Larger engines this is defiantly an issue. The plumbing may prevent this. A compression test will be a cheap way to see if there is anything major going on or at least a good cheap way to start and give you peace of mind when everything checks out. There are way better mechanics here than me for sure. Hope its something easy and cheap.
 
I don't think that's the issue, she died before it even went flat on the ground. It's a possibility though. I did a test run after checking the little stuff, I stayed moving for a while on a back road and had no issues. As soon as I hit a red light and sat there for a minute I lost power. Next light I shut the key off and restarted her, and my power was back when I took off. I did that cycle a few times, and seemed like a power off then on was helping me out. So I'm lost at this point.
 
Being gutless but running the whole rpm band, this does sound like a lack of fuel. (That tank vent line sounded like an A-1 suspect.) Restarting the bike resets the fuel pump. Is the fuel pump overheating or its connections corroded?

What side did it fall on, and what else is on that side?

Any damaged ground wires there? This can cause any unpredictable behavior once the voltage builds up, like affecting the ECU mentioned above.

Does the manual state exactly what happens during the startup sequence? That may provide other hints.
 
Fuel pump is brand new, I'm going to see if things change as I get closer to an empty tank. It fell on the right side (brake side), I pulled the fairing and didn't see anything that caught my eye. I've had fuel problems since I bought this bike, bad fuel pump is why I got it cheap. Replaced the pump and a bad O-ring was causing me to lose pressure in the tank, fixed that, then the high pressure filter wasn't giving me good flow, So I bypassed that and it ran flawless for 3 weeks or so. The inside of this tank was dirty, so I don't know if falling over cause some debris to get stuck in the pump screen, but that still doesn't make sense in relation to temperature. There's two lines coming off of my tank on the rear right. I remember blowing into them, and one or both wasn't easy to blow into. So maybe a partially clogged vent, causing vapor lock, giving me a shortage of fuel, but when I cut the bike off and on the fuel pump prime helps me out? Seems far fetched, but I've never had fuel problems until my buddies and I bought GSXRs
 
I'm going to get a fuel pressure gauge, and zip tie it to my dash. I'll watch it when it's running good so I know the pattern. Then when the gremlins kick in, I should be able to see a noticeable change. IF fuel delivery is my problem. When I was having fuel problems before, I would hit a noticeable flat spot around 7k and up. This time it's a total different feeling. Poor fuel delivery would explain the plugs looking lean.
 
I had a custom that I took to South Padre Island. It rained cats and dogs the whole time. When I got home I would leave the house on it and about 5 miles out almost at the exact fence post it would start back firing and cutting out.I would go back home start checking things out next day go out and same thing same place. After lots of mental fits and head scratching and hair pulling I figured out a tiny bit of moisture got inside my electronic ignition. When the bike cooled off it would condense in the bottom of the unit, once the bike got hot enough the moisture would vaporize and fog the electronics. So is there any chance that a programmer or ecu etc could have gotten moisture in it? maybe when it tipped. Its a stretch but its worth a thought. I absolutely hate electronic issues.
 
Just throwing ideas against the wall, do you have anything like a TRE that affects your timing? If you do (the reason I said ECU) have something retarding your timing that could give you a gutless feeling, them when you cycle your ignition it resets. Again I don't know just kinda thinking out loud.
 
She is all stock. Moisture is a possibility, but she can sit in the hot sun all day and have no problems when I leave work. It's only when the motor gets warm. I'll play with it some more today and see what I can come up with.
 
check that new in line filter you installed while you're at it, see if it got clogged somehow . . .
 
check that new in line filter you installed while you're at it, see if it got clogged somehow . . .
This is a good idea since the bike tipped sediment in the bottom of the tank would get dislodged and stirred up.
 
check that new in line filter you installed while you're at it, see if it got clogged somehow . . .
That did cross my mind, and I've had this tank off, upsideown, and shaken around so many times that I dont know about anything at the bottom of the tank. Update, it was hot and I got caught in traffic. Temp was about at where the fan comes on, I have a little less than half a tank. 1st gear, if I romped on the throttle it sputtered and hesitated and jerked a bunch. Higher gears with a quick twist just left me barely gaining speed and feeling flat. Took off again, and same thing. So I put her in neutral while coasting, key off, key on, fired up, put her in first and she came up no problem. Now that I think about it, in the beginning it was real bad and I had only a 1/4 tank. After I filled up was when it was running better, but still not like it was. I'm thinking I have a vapor lock issue, the more fuel in the tank, the cooler the fuel would stay. I still don't understand why tipping over would factor into this. I guess I'm going to pull the tank, pump, and filter out just to double check everything. Then back flow the vent tubes with an air compressor. Or I'll back flow the tubes first, since it's going to be easier.
 
This sounds like what my first busa was doing, it was a pile of rust collecting on the screen at the pump. It would run great, rust would start to collect, then low on power. Shut it off a couple seconds, the rust would drop, and it would fire up and run great. Then the process of the rust collecting on the screen would start all over. I went over EVERY dang thing until I pulled out the pump and saw the chunks of rust, finally figured it out.
 
This sounds like what my first busa was doing, it was a pile of rust collecting on the screen at the pump. It would run great, rust would start to collect, then low on power. Shut it off a couple seconds, the rust would drop, and it would fire up and run great. Then the process of the rust collecting on the screen would start all over. I went over EVERY dang thing until I pulled out the pump and saw the chunks of rust, finally figured it out.

I'm going to pull my pump today and see what I have going on. I'm hoping it's something dumb like that.
 
This sounds like what my first busa was doing, it was a pile of rust collecting on the screen at the pump. It would run great, rust would start to collect, then low on power. Shut it off a couple seconds, the rust would drop, and it would fire up and run great. Then the process of the rust collecting on the screen would start all over. I went over EVERY dang thing until I pulled out the pump and saw the chunks of rust, finally figured it out.

You were right, I pulled the pump and there was some thick chunks of what appears to be rust or something. When she fell over it must have dislodged something. I'm hoping this fixes my problem. I should have known it was something like this, considering the only problems I've had with this bike are fuel pump related lol.
 
I need to look into how to coat my tank or get rid of the rust in it. Crazy that these tanks have problems, it's not a 30 year old bike. Damn Suzuki!
 
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