2000 Throttle Issue

[LEDBiker]

This is my first Busa. It's a 2000. No mods except a 6 inch stretch and D&D slip ons. No power commander or anything else that I can see.

Odometer says 22,000 miles but I don't believe it. The registration shows the reading the last time it was registered and it says 27,000. On top of the airbox I found a sticker that says it was serviced at 31,000. The odometer and speedo also read miles and it is a Canadian bike so I can only assume someone swapped the cluster at some point. Wrecked? Its not a rebuilt title and I can't find any obvious signs of damage.

Anyhow, I have a weird throttle issue. Between 2000 and 3000 rpm it stumbles coming off or on it. Even trying to hold a steady RPM it will come on and come off if the RPMs are between those ranges. I checked the throttle cable and its fine.

If this had a power commander I'd be tempted to blame the mapping. Since its not that I am wondering if there is some sort of throttle position sensor that is going bad but I don't know if it has one. I am in the lighting business and its acts as if there is a bad spot on a fader or dimmer control. When they wear out or get dirty they flicker at certain points, or cut in and out.

Is that what it is? Is there an easy fix like taking it apart and cleaning it or do I need to order the part.

Other than that, this bike is the poop. Loving it.

 

[jermzfree]

Your bike has some red flags. If you haven't already done this, change all the fluids and ck everything over. The bike has been taken apart and messed with by someone dishonest unklowledgable. Bad combination! True mileage hidden and not tuned with aftermarket cans. Maybe dirty throttle bodies or intake valves from not being tuned properly. It will run better if you put the stock cans back on.
The bike does have a TPS and is easy to check the ohms and voltage to verify its still good. Also needs to be in adjustment!

 

[LEDBiker]

Thanks.

When I got it, a friend and I went over it as best we could. Brake pads were completely worn out. The drive cushions were beat right out of it. Someone had the plastics off and did a really shitty job repainting it. When they put it back together it was missing $300 worth of screws and fasteners... if you can imagine. We changed all the fluids, compression check, checked to make sure the recalls were done (they were), made adjustments, put new tires on etc.

I'm not complaining much. As soon as I went to look at it I assumed it had more miles than what was showing just by the overall appearance. We somehow both completely missed the tag on the airbox cover. Duh. I got it for a good price and other than this remaining issue it runs well. Had it on the dyno at a local bike show and it put out 165 at the wheel. I'm happy overall. I don't mind putting money into it to make it better. Over the winter I will be upgrading the brakes, new chain and a new paint job. I'll get the valves checked and adjusted as well.

 

[David Offor]

This is my first Busa. It's a 2000. No mods except a 6 inch stretch and D&D slip ons. No power commander or anything else that I can see.

Odometer says 22,000 miles but I don't believe it. The registration shows the reading the last time it was registered and it says 27,000. On top of the airbox I found a sticker that says it was serviced at 31,000. The odometer and speedo also read miles and it is a Canadian bike so I can only assume someone swapped the cluster at some point. Wrecked? Its not a rebuilt title and I can't find any obvious signs of damage.

Anyhow, I have a weird throttle issue. Between 2000 and 3000 rpm it stumbles coming off or on it. Even trying to hold a steady RPM it will come on and come off if the RPMs are between those ranges. I checked the throttle cable and its fine.

If this had a power commander I'd be tempted to blame the mapping. Since its not that I am wondering if there is some sort of throttle position sensor that is going bad but I don't know if it has one. I am in the lighting business and its acts as if there is a bad spot on a fader or dimmer control. When they wear out or get dirty they flicker at certain points, or cut in and out.

Is that what it is? Is there an easy fix like taking it apart and cleaning it or do I need to order the part.

Other than that, this bike is the poop. Loving it.

Just read your problem, good call on the dimmer light comparison, it points to the TPS, worth a throttle body sync, after the TPS has been eliminated, 165 at the back wheel on a stock motor, is very good, the gen one engines are very tough and can take a lot of abuse and poor maintenance (I know this first hand).
Hope you get it sorted.

 

[LEDBiker]

Thanks.

I love riding it, its a good machine. I plan to spend some time and money on it over the winter but its been a good ride so far.

I am a little annoyed that I don't have any idea how many miles are truly on it but I can only do what I can do.

 

[LEDBiker]

I've checked the TPS adjustment in dealer mode as per the video and the indicator is centered as it should be. There are also no codes.

 

[LEDBiker]

My situation has gone from bad to worse. Now the bike won't start properly. It will start and run if I hold the throttle but it runs poorly unless revved above 3K. Was working perfectly until I lifted the tank up to look at the TPS. I see that the TPS has a line drawn on it from the previous owner. In dealer mode it still is showing at the center point. Still no codes. Try to fix one minor thing I've been putting up with for months and now I have a bike that won't run. Awesome.

 

[LEDBiker]

Now I am at least back to the original problem. I found my second problem when I took off the fuel tank, managing to spray gas everywhere because there is no way to shut off the flow and you have to clamp two hoses. Arrrgh. When I lifted up the tank, something snagged what looks like air lines leading to the fuel pump and one came off. Back on and at least it runs like it did. I am going to take it for a ride and post a video of the original problem.

 

[LEDBiker]

Interesting turn of events. I no longer have my original problem. Before I left, I slightly loosened the TPS screws and gave it a light tap. The indicator went to the bottom of the display and my idle dropped maybe 100 rpm but it still idled well and throttle response was fine. I decided to take it for a ride as it was just out of curiosity. I was expecting it to work like crap but it did the exact opposite. It worked perfectly. No stumble at lower rpms and throttle response is smooth all the way to red line. I ended up staying out for a few hours to enjoy the sun and was very pleased with its performance. When I got back I put it back in dealer mode and its still showing the indicator at the bottom. I left it as it was for now.

If it starts acting up again I will replace the TPS. It is probably marginal with a worn spot if its anything like a standard pot. Perhaps I dislodged a piece of dirt or carbon.

Thanks for the help.

 

[Busabim]

you need to investigate stock external fuel pump and filters as it will probably strand you at some point in the future. Search this forum for thread . I would also add a secondary low pressure fuel pump. Change all gas line every 2 years max.

 

[David Offor]

My situation has gone from bad to worse. Now the bike won't start properly. It will start and run if I hold the throttle but it runs poorly unless revved above 3K. Was working perfectly until I lifted the tank up to look at the TPS. I see that the TPS has a line drawn on it from the previous owner. In dealer mode it still is showing at the center point. Still no codes. Try to fix one minor thing I've been putting up with for months and now I have a bike that won't run. Awesome.

You said it started acting badly after lifting the fuel tank? I don’t think the TPS would give you the inconsistent running problems, that you’ve mentioned, the early out of tank fuel pump set ups, have a long gauze fuel filter, attached to that ridiculous ‘fuel tap’, remover the two Allen bolts and take the filter out, check it’s clear the early Busa tanks suffered from rust, it’s possible lifting the tank up and down has dislodged some sludge in the tank and is blocking/unblocking the outlet, from the tank, to the pump the out of tank fuel pump set up is problematic and it’s not a big deal to upgrade to the intank set up, if you can source 2001 onward parts.

 

[jermzfree]

My situation has gone from bad to worse. Now the bike won't start properly. It will start and run if I hold the throttle but it runs poorly unless revved above 3K. Was working perfectly until I lifted the tank up to look at the TPS. I see that the TPS has a line drawn on it from the previous owner. In dealer mode it still is showing at the center point. Still no codes. Try to fix one minor thing I've been putting up with for months and now I have a bike that won't run. Awesome.

Check for an unplugged vacuum line, which would cause the bike to stumble and die at low rpm.