mikesail Posted July 7, 2006 Share Posted July 7, 2006 Does anyone have a Bird knock sensor to sell? I'm pretty sure the one on my bike is bad, and would like to swap out the unit to test my theory. My bike is a 2003, but I imagine that all the FI bikes use the same unit though I can't check that. Otherwise, what is the best place to order such parts? Quote Link to comment Share on other sites More sharing options...
exskibum Posted July 7, 2006 Share Posted July 7, 2006 Does anyone have a Bird knock sensor to sell? I'm pretty sure the one on my bike is bad, and would like to swap out the unit to test my theory. My bike is a 2003, but I imagine that all the FI bikes use the same unit though I can't check that. Otherwise, what is the best place to order such parts? I don't, and don't even know where it's located, but now you've got me curious and I'll consult my service manual. TO order, call Gary at University Motors. Should be able to find lots of glowing reports and contact info if you do a search on this site for him. Quote Link to comment Share on other sites More sharing options...
SBBXX Posted July 11, 2006 Share Posted July 11, 2006 Ya learn sumpin new every day. I never really thought for a second there was an actual sensor. I believed it was just a program in the fuel injection. Quote Link to comment Share on other sites More sharing options...
bartonmd Posted July 11, 2006 Share Posted July 11, 2006 Ya learn sumpin new every day. I never really thought for a second there was an actual sensor. I believed it was just a program in the fuel injection. It is a program in the FI... based around what the knock sensor is seeing (or rather, hearing)... BTW, why do you think the knock sensor is bad?? Mike Quote Link to comment Share on other sites More sharing options...
mikesail Posted July 11, 2006 Author Share Posted July 11, 2006 I have a bike that gets about 31 mpg regardless of how I ride. either 60 mph on the slab or riding canyons, I still see about 31. It has been exactly this way since I bought it brand new, now 21k miles later have never seen a change.Note: just put on a pcIII, now it is about 33. Based on how hard it is to wheelie mine, I think my torque is down a bit as well. Without riding another bike though I can't be sure about that comparison. The other engine sensors seem to give proper values so my suspicion turned to the knock sensor. One way to get these symptoms from a engine would be to have a retarded spark. If the knock sensor were always reporting detonation, then the bike would always be retarded. I did pull the sensor off and measure its output on a scope while tapping it on a table. It seems to be extremely sensitive, though I don't have a known good unit to compare and i cannot find any info on response levels. Thus if I can swap for another unit I can see if this is the issue. If it is not I move on to check cam timingand then ???? Quote Link to comment Share on other sites More sharing options...
bartonmd Posted July 11, 2006 Share Posted July 11, 2006 fwiw, a knock sensor is always like that... There's a circuit in the ECM that filters out all the wrong frequencies, and leaves the frequency it's looking for... Also, usually, if the knock sensor is just unplugged, the engine will see that it's not there and back timing off, so it may be as simple as a wire not making connection... Did you take the connector off of the ECM and ohm out everything down to the hooked up knock sensor? Mike Quote Link to comment Share on other sites More sharing options...
Guest rockmeupto125 Posted July 11, 2006 Share Posted July 11, 2006 Have you had the bike dyno'd, and if so, does it show a low power situation? Have you checked the timing with a light? How about disconnecting and shorting the leads to the knock sensor? The ECU advances the ignition if the voltage from the sensor is not spiking greater than the noise voltage. Would giving it no signal but maintaining continuity in the circuit by jumpering the contacts allow it to advance (there is a set limit), or would it just generate a code 25 error? Quote Link to comment Share on other sites More sharing options...
mikesail Posted July 11, 2006 Author Share Posted July 11, 2006 Joe and Mike, thanks for the discussion. here are my responses. The bike generates a code if you unplug the sensor. This seems to indicate that the connection to the sensor is good, else it would not know it was unplugged. I'm guessing that it expects to see a certain amount of signal to know that the sensor is connected. I have not had the bike dyno'd. my seat of the pants dyno shows max throttle in first gear will just slowly lift the front with my 205 lbs sitting near the tank. Can't get it up in second no matter what. It seems from reading discussions that the bird normally wheelies easier, thus my belief that my torque is a little low. I don't know how you check timing on the FI bike, can you tell me what the provisions are for measuring and what the numbers should be at idle and somewhere mid range? I don't expect that it would be happy with shorted leads, since the sensor is a piezo element which looks capacitive. I have to believe it would detect a fault as it does with an open, since an open is basically the same as no signal. Quote Link to comment Share on other sites More sharing options...
Guest rockmeupto125 Posted July 11, 2006 Share Posted July 11, 2006 Joe and Mike, thanks for the discussion. here are my responses. The bike generates a code if you unplug the sensor. This seems to indicate that the connection to the sensor is good, else it would not know it was unplugged. I'm guessing that it expects to see a certain amount of signal to know that the sensor is connected. I have not had the bike dyno'd. my seat of the pants dyno shows max throttle in first gear will just slowly lift the front with my 205 lbs sitting near the tank. Can't get it up in second no matter what. It seems from reading discussions that the bird normally wheelies easier, thus my belief that my torque is a little low. I don't know how you check timing on the FI bike, can you tell me what the provisions are for measuring and what the numbers should be at idle and somewhere mid range? I don't expect that it would be happy with shorted leads, since the sensor is a piezo element which looks capacitive. I have to believe it would detect a fault as it does with an open, since an open is basically the same as no signal. Timing...pull the right lower fairing and the timing plug, trigger off the number 1 plug, and the marks should line up, as well as advance with throttle. (download the manual) I figured that the senser would generate a fault without continuity....which is why I suggested jumping the connection. But I somehow knew you had an answer for that one well before I came along. Put an antenna by it...maybe that will generate enough fuzz to get it to work....LOL. Quote Link to comment Share on other sites More sharing options...
bartonmd Posted July 11, 2006 Share Posted July 11, 2006 fwiw, my 'bird will power wheelie in first if I get on it about 4k, then about 7k, it'll come up, but if I go WOT from idle up in first, it'll just slowly float the front end... Won't do it in second without trying... Mike Quote Link to comment Share on other sites More sharing options...
SBBXX Posted July 11, 2006 Share Posted July 11, 2006 You didn't say if you reset the computer. If you haven't, maybe you should try that first. Quote Link to comment Share on other sites More sharing options...
mikesail Posted July 11, 2006 Author Share Posted July 11, 2006 no change after power cycling the ecu. i will attack the timing port when I get free time later. Quote Link to comment Share on other sites More sharing options...
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