awood12345 Posted April 3, 2013 Report Share Posted April 3, 2013 Hi Guys, I need ideas, I've tried everything I can think of apart from making a new loom. My race bike is misbehaving and will not rev past 10k most of the time, some times it does but it is lumpy. I put it on a dyno to test it and changed the fuel tank, pump, plugs and coils (from my working road bike) this didn't solve the issue. Then I put a multimeter on it whilst it was on the dyno and the power to the coils dropped down to below 10v, so I bypassed the loom and ran a new live straight from the battery to the coils and it ran fine. So I know the fault is electrical. I've replaced the live wires (gray and orange/white) in the loom and its not fixed it yet. Any ideas? I'm running out of ideas and if I have to take it to a specialist then I may have to miss a racing round as it is next weekend. Wiring diagram: https://www.dropbox.com/sh/qynk3ijerib6m5o/V4KbsEQ-y_?n=88095305 Link to comment Share on other sites More sharing options...
Evilchicken0 Posted April 3, 2013 Report Share Posted April 3, 2013 Is it a Grey import from Japan ? It sounds like a speed restricted CDI, if they don't get a signal from the speedo at 0kmh they can restrict. Link to comment Share on other sites More sharing options...
VanWinkle Posted April 4, 2013 Report Share Posted April 4, 2013 Cam Chain off a tooth?. Link to comment Share on other sites More sharing options...
gurninman Posted April 4, 2013 Report Share Posted April 4, 2013 Cam Chain off a tooth?. Cam Chain off a tooth?. That's exactly the problem a mate had with a K4 thou , presenting the same symptoms as the OP Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 Is it a Grey import from Japan ? It sounds like a speed restricted CDI, if they don't get a signal from the speedo at 0kmh they can restrict. the speedo is on the output shaft isnt it? That's exactly the problem a mate had with a K4 thou , presenting the same symptoms as the OP if putting a wire from battery to coils +ve fixed it then maybe not? did it make the normal bhp etc? was this from the actual battery on the bike, or a slave one seperate to the bike. Does the batt voltage go up when you rev it? (ie the reg/rec ok? Go back to the dyno and ensure putting a wire on it actually does fix it. Is the battery ok? And it's got to be worth trying the ecu. Link to comment Share on other sites More sharing options...
awood12345 Posted April 4, 2013 Author Report Share Posted April 4, 2013 Is it a Grey import from Japan ? It sounds like a speed restricted CDI, if they don't get a signal from the speedo at 0kmh they can restrict. Nope genuine UK model from crescent, it ran nice last year but it didn't this one. The coils are fired by the ECU cutting the negatives so that the field in the primary winding collapses which causes the secondary winding to generate the spark. Has the ECU got a decent -ve? I haven't checked but this is one of my other issues. I everything seems fine untill 10k under load so it needs to be on a dyno to do it. Cam Chain off a tooth?. Unfortunatly not that simple, it is not mechanical. If you're saying that you used a multimeter, presumably set on AC, to measure the voltage at the coils on the primary side then it's not surprising that the indicated voltage dropped off as the revs increased. The signal that the primary side of the coil receives from the ECU is a square wave varying frequency 12-0-12V signal and at 10,000rpm your looking either 167hz or 334hz, depending on whether it's a lost spark firing sequence or not. You'll need an oscilloscope to measure the coil primary signal. Try slaving in a known good ECU. I used the multimeter between the battery and the coil so it wasn't switching just showing the supply voltage. I can only assume it made normal BHP as I didn't have a dyno form before but the dyno guy said the curve was good and there no fueling issues. It seemed to be right on power and have good torque. Yeah battery voltage reads fine and increases with revs. I've also swapped the reg/rect and checked the alternator. I did fix it on the dyno with that wire and it sorted it 100%. I suppose your right the next thing is an ECU. Cheers for the ideas guys, I think I'm getting to the point I'm going to have to take it to a dealer. Link to comment Share on other sites More sharing options...
lorenzo Posted April 4, 2013 Report Share Posted April 4, 2013 Does the gsxr have anything that'll stop it revving out fully like a side stand switch or a neutral sensor for example, something that acts as some sort of "can't hammer it at a standstill" device that might be stuck? Link to comment Share on other sites More sharing options...
awood12345 Posted April 4, 2013 Author Report Share Posted April 4, 2013 Nice idea but I don't think there is anything like that and the side stand switch is wired together. The strange think is it will rev to the top of the gauge on paddock stands in and out of gear. it is only under load that it has issues. I'm thinking it could be a coroded wire that I can't find that only struggles under high load? Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 strange things going on with the tps? Link to comment Share on other sites More sharing options...
awood12345 Posted April 4, 2013 Author Report Share Posted April 4, 2013 Theres a TPS gauge on the dash of a GSXR in dealer mode and it seems ok. It is not a absolute wall on rpm, it pops and crackles around it. Even stranger is it can can somtimes rev though it! Link to comment Share on other sites More sharing options...
jaycee Posted April 4, 2013 Report Share Posted April 4, 2013 Cam Chain off a tooth?. Nice idea but I don't think there is anything like that and the side stand switch is wired together. The strange think is it will rev to the top of the gauge on paddock stands in and out of gear. it is only under load that it has issues. I'm thinking it could be a coroded wire that I can't find that only struggles under high load? There's a bloke on a forum that VanWinkle and I use that had the exact same problems on a GSXR1000. It turned out his cam chain was out by a tooth due to a collapsed CCT and stretched chain. It would rev out on the stand but under load it died at 10k Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 got to be worth checking, wont cost anything. Link to comment Share on other sites More sharing options...
Barry Posted April 4, 2013 Report Share Posted April 4, 2013 Alan, how long would it take to swap out the loom? I'd look at doing that next. Have you done anything to it over the winter? Maybe ask Giles if you can pinch a few bits off his old bike to test? Link to comment Share on other sites More sharing options...
2Smoke Posted April 4, 2013 Report Share Posted April 4, 2013 Has it got a tilt switch? Link to comment Share on other sites More sharing options...
awood12345 Posted April 4, 2013 Author Report Share Posted April 4, 2013 Barry, Loom is next I think, Giles he has offered me loan of bits but my road bike has bits I can borrow from. Millemille, Yeah that is what I thought but that wire I ran solved the issue so surely it has to be? 2smoke, Yeah it has a tilt but it is in position and seems ok, it pulls through peak torque (most G force) ok only top end. I've booked it in with steve jordan monday, hopefully he can sort it, this way he can test any fixes on the dyno as he tries them. Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 If it will rev to the red line on the paddock stand it's incredibly unlikely to be an electrical issue related to the coils or them firing. How can it be? The current drawn by a coil or frequency at which it fires doesn't change one iota with whatever load the engine is under. but the voltage required to make a decent spark goes up with engine load. so if this is what is happening, the reduced volts available at the coil will mean less volts available at the plug and the motor will stop making power at a certain revs.which is what made me think if the tps is screwy it might be doing strange things, but i doubt it now thinking about it. Link to comment Share on other sites More sharing options...
Barry Posted April 4, 2013 Report Share Posted April 4, 2013 Barry, Loom is next I think, Giles he has offered me loan of bits but my road bike has bits I can borrow from. Are your coils the individual stick type? Have you tried the ones from your road bike? Could be a coil or two breaking down under high load? Link to comment Share on other sites More sharing options...
awood12345 Posted April 4, 2013 Author Report Share Posted April 4, 2013 Stick type and I've changed them all and the plugs. Link to comment Share on other sites More sharing options...
Bernster Posted April 4, 2013 Report Share Posted April 4, 2013 Sent you a PM chap. Let me know. Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 No it doesn't. Sparks are generated by collapsing a field, not creating one. The load on the primary windings is created when the supply is withdrawn from the primary and the field in the secondary collaspes, casuing an outrush which generates the spark. The supply to the primary is reconnected, the primary recharges, inrush, in exactly the same time whether the engine is doing 1rpm or 10,000rpm. Voltage supplied, current drawn and power consumed are all constant for each spark generated. If replacing the +ve supply to the coils, via the ECU, with a solid wire from battery +ve to the coil fixes the problem in a repeatable manner despite whatever other variables there may be then it's either the ECU or a +ve supply issue. yes it does! i didnt say it wasnt an ecu issue, or a supply issue. the volts required to fire the mixture goes up as the load increases. so it follows that if the volts going to the coils reduce at 10k rpm the amount of charge the plugs will see is less. eidt speeling Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 http://www.ngksparkplugs.com/tech_support/spark_plugs/p5.asp?mode=nml i havnt got me handy crib sheets handy, but ngk mutter about insufficient primary/sec voltage Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 another thought - try the battery off the road bike. Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 Yes, exactly. So summats clearly up at t'mill. What im saying is becauseCos the volts at the coil ( and presumably the rest of the bike) drops it misfires/wont rev past 10k under load. Higher the load the more volts you need to light the mixture. Fact. The faster you rev the less time you have to charge the coil. Link to comment Share on other sites More sharing options...
porter_jamie Posted April 4, 2013 Report Share Posted April 4, 2013 Emerald ecu has mappable dwell times. To what end I know not. The previous version was set at 3ms and the coil we used was rated for 1.5ms. It went like stink for a couple of sessions then stopped. New coil same deal. Found the coil drg and worked it out and then got emerald to add dwell to firmware. Link to comment Share on other sites More sharing options...
awood12345 Posted April 9, 2013 Author Report Share Posted April 9, 2013 Problem found. I would have never diagnosed this! The kill switch is broken. There must be a bad joint in it because at certain rpm and resonance it was flicking the ignition on an off enough to interupt a spark but too quick to re-set the ecu and other systems. This is why i couldn't find a fault without it running. Link to comment Share on other sites More sharing options...
porter_jamie Posted April 9, 2013 Report Share Posted April 9, 2013 Glad you got it it sorted! Good skills whoever found that. Link to comment Share on other sites More sharing options...
awood12345 Posted April 10, 2013 Author Report Share Posted April 10, 2013 It was one of the guys at Steve Jordan Motorcycles. Top Job. Link to comment Share on other sites More sharing options...
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