00 Busa surging and sputtering under 3000 RPMs

[rl7-2]

looks like my problem wasn't the power commander afterall. I believe the op's problem still likely could be. If you can't upload to it, something is obviously wrong with it.

I was mistaken before, my bike would run without a pc, but it stumbled and bucked badly at 3-4k due to the airbox mod. This sounds like the op's current problem.

Mine runs really bad under 3k or so in low gears most of the time and seems to get worse the longer the ride andlower the gas. I suspect the fuel pump is failing. I have an in-tank walbro type (likely a knock off). The pump is gas cooled so as the gas gets lower and hotter, the pump's performance deteriorates even more. Plus I can sometimes actually feel my fuel tank getting warm and my actual gas mileage is significantly higher than what the computer reports. I figure it might still work acceptably at higher rpms because the stator is putting out a higher voltage.

[archer1]

there is something you can use to get codes or idea what is causing the problem
it is a small harness with a little micro on/off switch that plugs into the bike under the back seat somewhere
not too sure yet just got Busa on Saturday and have the switch but have not had to try it yet
it refers to it in the manual
hope this helps

[archer1]

what is the op's problem?? mean

looks like my problem wasn't the power commander afterall. I believe the op's problem still likely could be. If you can't upload to it, something is obviously wrong with it.

I was mistaken before, my bike would run without a pc, but it stumbled and bucked badly at 3-4k due to the airbox mod. This sounds like the op's current problem.

Mine runs really bad under 3k or so in low gears most of the time and seems to get worse the longer the ride andlower the gas. I suspect the fuel pump is failing. I have an in-tank walbro type (likely a knock off). The pump is gas cooled so as the gas gets lower and hotter, the pump's performance deteriorates even more. Plus I can sometimes actually feel my fuel tank getting warm and my actual gas mileage is significantly higher than what the computer reports. I figure it might still work acceptably at higher rpms because the stator is putting out a higher voltage.

[issdar]

It means the OPENER of this thread. Think the airbox mod and/or fuel pump maybe be causing my surge but whats weird its gotten better over time since I originally felt it seems. Or then again maybe just got used to it. Funny thing is I got an airbox off of ebay a while back and asked them if it still had secondary valve still intact AKA no small airbox mod and they said it had it still. I got part and what do you find no secondaries! I was mad but haven't returned part for refund yet its a pain.

[Bertactive]

Had the same issue but After changing my pump in my 00 to a new one and my problems got slightly better my pump blew again replaced it and moved up to the injectors at the same time, injectors looked clean but the new ones made my probes disappear I suggest stock Honda s2000 injectors to save on cost I have MPS injectors on order so I can get back to you and let you know how they run with my 08 factory pump

[Bertactive]

Just to follow up pump worked good injectors were gone as well once they were replaced bike ran like a champ

[tccycles84]

i got an 2000 that doing the same thing just started looking into this

[c0ke]

have u tried changing map sensor?

[Rodomontade]

I have the EXACT same problem as the OP.

Mine is a 1999.

I have replaced the IAP Sensor, AP Sensor, Pulled Injector Screens, Pulled Fuel Regulator Screen, Cleaned Fuel Pump and Related Screens, Synced TB's, Checked ALL Vacuum Hoses and Confirmed The IAT Sensor is Good. Centered The TP Sensor, Pulled My Power Commander Completely Off. Also Changed Plugs. Even Took The Screen Out Of The Tank And Cleaned It!

All This and Still Have The Same Problem!

I STRONGLY Suspect The TP Sensor Has A Dead Spot. When You Think About It... This Is Where Most Of The Throttle Movement Occurs During Cruising At Speed.

I Do Not Suspect The CMP or CKP Sensors, As Some Have Suggested. These Sensors Would Show Problems All Over The Throttle Range and Not Just Below 3000 rpm Or Partial Throttle.

I Will Be Changing The TP Sensor In The Spring With A Brand New Factory Part. (Ran Out Of Nice Weather To Continue Troubleshooting).

I Will Post Back Here After Trying That.

Seems This Problem Is Getting More and More Common.

[broseboro332002]

after going thru a throttle body sync and replacing the throttle position sensor. I finally diagnosed the issue at my local dealer went and have a compression leak down check along with valve spec check. They found my cams had came out of timing so $400 later at the shop she is running back to normal. I will be picking my 00 busa up tuesday I will give the full diagnosis then on here.

[broseboro332002]

I got the bike back today and looked over the diagnostics found out that the OEM CAM TENSIONER went bad cause the cams to jump teeth and made it run horrible so I just went today and bought a APE Manual Cam Tensioner. The best investment that could save a engine and costing you $400 to retime your cams.

[dadofthree]

Glad you got it fixed. I'm thinking there was a recall or at least a known problem with the cam tensioner on early models.

[broseboro332002]

if there was I wander why the dealership didnt tell me about it... Money hungry dealerships...

[jphilipson]

From the get go I was thinking something cam/valve related - bad idle and bad performance at low RPMs is a common side affect of such.

[broseboro332002]

From the get go I was thinking something cam/valve related - bad idle and bad performance at low RPMs is a common side affect of such.

I thought it was the valves but, they were in spec. Suggest all riders if you have a Gen I busa and having the low RPM stuttering issue I would look at investing into a APE manual cam tensioner.

[SKYGZR]

I thought it was the valves but, they were in spec. Suggest all riders if you have a Gen I busa and having the low RPM stuttering issue I would look at investing into a APE manual cam tensioner.

And where does one acquire this item, and install procedure?

[QWKENAF]

Go to APE Racing in the sponsors and you can find it there

[Wodgepow]

Help - I have a 01 Busa with the same sputtering problem, error code C25 which the service manual says is : Ignition coil, wiring/coupler connection, power supply from battery. Did you find a solution to your problem that is related to these? I have a good battery and it runs great half the time and always starts out strong. I'm fishin' and would appreciate help.

[Stites]

Help - I have a 01 Busa with the same sputtering problem, error code C25 which the service manual says is : Ignition coil, wiring/coupler connection, power supply from battery. Did you find a solution to your problem that is related to these? I have a good battery and it runs great half the time and always starts out strong. I'm fishin' and would appreciate help.

Well if you have a code that's where I would start...........it's not uncommon for coils to go bad. Borrow a set from a friend and swap them out and troubleshoot from there.

Scott

[race24x]

Hey guys another new year same iussue. I didnt work on it much at all over the winter. I am looking at a few suggestions I thought I would try.
1 Someone mentioned voltage. I did have an issue with my voltage regulator out back and had to fix some burnt wires. Sometimes I feel like my headlight is getting brighter and lower but I cant tell for sure it could be me imagining it.
2 I bought a TPS and I am going to try that
3 Rebuild and clean injectors and flow test.
4 MAP sensor
5 IAT senssor
6 WHat is the vacuum piece on the back of the airbox that one member mentioned was his issue
7 WHat are the vacuum lines everyone mentiones to check they are not plugged or pinched