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Did the mod, works like a charm. Involved a fair bit of fiddling with the connectors, dropping the tank on ones fingers and suchlike. Disconnected the sensor to test if I got the right one, strangely enough not only did the FI indicator light up, all of them did. :huh: Plugged in the resistor, all went out. Secured with electrical tape, disconnected the battery for 10 minutes, went for a ride, received pleasure. :smilebig:
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Hey Gareth i also bought my Bird about a week ago.2005 Model.Today she started with the same thing as I was on a run.The rough riding as you describe it.I was thinking.Is it possebible that a regulator is starting to go?Please if you get a solution to the problem let me know
 

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I recently bought a stock standard 2005 Blackbird. A few days after I bought it I noticed the lean surge problem (for anything between 2k and 4k rpm). It was getting damn annoying for the last 2 weeks and then I found this thread. Thanks for all the info guys. I made the O2 Sensor eliminator this morning and went for a ride. What a difference. It is a huge improvement. I will need to see what the mileage is like in a few weeks and I do wonder if the catalytic converters may end up with a problem. I hope not. But I love this bike again (like I did after the test ride).

I've also seen via the net that this problem isn't restricted to Blackbirds. It seems this crazy idea of having the mixture adjusted in a closed loop is a problem for many types of bike. Bizarre why the manufacturers don't do something about this bad design.

Anyway, I wanted to add some info that I learned in the last few days. And some pics.

To get under the tank you need to take the seat off and undo the two bolts at the rear of the tank. The two bolts each have a big rubber grommet beneath them, so be careful not to lose them. When you lift the back of the tank be careful to not pull out any fuel lines (there seem to be about 3 of them right underneath the tank and I found at least one was concealed and nearly stretched too far when I lifted it).

You also need to pull the black lugs out of the rubber grommets on the plastic side panel (see the red arrow on the picture below). Prop up the back of the tank with a piece of wood. Or if you want to get serious you can probably lift the front of the tank by this method (Lifting the tank on the Honda Blackbird). I didn't.

To find the O2 sensor plug, trace the O2 sensor wire from the right hand side of the bike (by the brake pedal) up under the tank to where it goes under a black rubber cover near the left side of the bike. Lift up the black rubber and you'll find the plug (see yellow arrow on picture below and the zoom view on the second picture).

View attachment 29035 View attachment 29036

To undo the plug, you need a small screwdriver. Slide it in from the top plug side (the top left one in the photo) and lift the small lever. The plug then comes apart when you pull them.

The O2 sensor has 4 wires, 2 for a heater element and 2 for the sensor readings. The black/white and black/green wires are the heater (O2 sensors use a small heater to heat the exhaust gas so it can be tested by the sensor). The green/orange and orange/white wires are for the sensor. The sensor generates electricity down these wires of between 0 and 1 volt depending on how much oxygen is in the exhaust gas (and therefore how lean or rich the mixture is).

The 330 Ohm resister (Orange,Orange,Brown,Gold stripes) needs to go between the two heater wires (black/white & black/green wires). This then fools the ECM (ECU) into thinking the heater is still attached. The other two wires can be left disconnected because the ECM will just see that there is zero voltage on these wires and will therefore think the engine is lean and so not try and lean it out (so it will tell the engine to use a constant fuel injection time from the ECM map, so no surge, yay).

After I took the photos, I used a cable tie to hold the resister in place and then put a bit of tape around the plug plus I taped the plug that goes to the O2 sensor so it doesn't fall down and get caught up in something.

When you put the tank back down, you need to make sure the side lugs engage (red arrows on photo) and you may need to push the tank forward a bit (if it has slipped back) so you can get the 2 bolts back in place.

One thing I didn't do was disconnect the battery as suggested by JohnS on page 4 of this thread. I haven't been able to find any info on adaptive learning in the Blackbird ECM and I figure if there is, it will sort itself out over time as I ride more. I'd love to know if anyone has any more info on Honda Blackbird ECM adaptive learning and what it may or may not do.

Good luck.

Hi everybody,

I read the whole thread and yes this issue was irritating me so much that I have searched on every cbr and gsxr forum till I hit this thread.

as aroberts mentioned the 330 ohm resistor is to be placed across the wires connected to the heater element not the sensor part of the lamda/02 sensor, is that meaning I could just connect the 2 black wires to the heater and disconnect the other 2? doing it this way ensures the FI light is off while the contacts to the sensor are open sending a signal to the ECU that the mixture is lean enough.

please feed me back weather if it's possible to mod it that way or not ?

regards
 

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Hi.

Yes, I believe you could just disconnect the sensor wires and leave the heater wires connected. That would mean the small heater would stay on but probably not a big deal as it would be on anyway when the sensor is operating normally.

I did think of doing this and just cutting one of the sensor wires. But I used a resistor in case I ever wanted to put the sensor back on.

I suggest disconnecting the plug and then going for a ride (with the FI light on, it won't hurt anything) just to make sure it cures the problem, before making any mods.

One thing of note is that I am on to my second Blackbird now. The second is a 2006 (old one was 2005) of similar mileage and it doesn't have the problem to the same extent. In fact I haven't bothered doing the mod on the second one. You can still notice the surge but it is fine to ride using the sensor, unlike the first Blackbird which was really annoying at slow speeds. I guess it is down to other factors. Both have the standard computer etc.

Good luck.
 

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I know this is a old thread, but I had the same issue with my 2004, 48000km I put in the resistor, which reduced the effect, then when I got home 900km later replaced the fuel regulator, then plugged the o2 sensor in again,,,, totally cured it.....
 

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I use my BB for commuting so if I had this problem I'd just fit a new o2 sensor as I still want the economy

I doubt in any of these cases that its an ECU problem and that its just a faulty or worn out sensor.

What I think is the problem in the first place is people using additives in the tank which will destroy the sensor (remember Tesco petrol a few years back in the UK ?)

So it makes no difference whether yours has done 1000 or 100,000 miles when this happens.

Other people seem to think its a good idea to add toluene to the tank for example.

Even some instant gasket sealers can damage the o2 sensor.

lastly, if your BB has been bounced down the road at some point in its life then that could have damaged the sensor but if you don't mind drinking the juice and potentially clogging your catalyst (if you've still got them) then I suppose the mods are fine as its your choice after all.

Ps, This is an old thread so i guess these people don't even exist anymore:D
 
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