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Discussion Starter · #1 ·
This one really doing my head in!
Just finished my longtime chop build incorporating a 750WP motor into a hand built hardtail frame, using all WP electrics, loom, coils, relays, etc, the motor starts real easy on the button first time every time and runs really sweet, couldn't be happier.
My big problem is that I need to ride it to my regular bike shop to get it MoT tested and guess what? - I can't because as soon as I put the bike in gear the motor cuts, every time, whether I use first or second and I'm pulling my hair out!
Before anyone yells 'Kickstand switch' let me tell ya it's fine, I've stripped it, cleaned it and I jump in the seat, turn the key, if the stand is down I get nothing, flick it up and she'll start up instantly, drop it back down and the motor dies so no wukas there. The neutral gear indicator working and illuminates the warning light. I've tried swapping both the kickstand diode and kickstand relay with spares I have of each - nothing changes, bike still starts and runs but hit a gear and she dies 馃槱
Incidentally the clutch disengages and today I rolled the bike down a slope in third to see if it would bump but motor was turning over but no firing whatsoever, and the indignation at having to get a guy with a car to tow me back up the goddam hill馃槵
I been hoping to get some riding on it before winter sets in so if any of you dudes have had any issues of this nature and overcome them somehow I'd sure appreciate your advice.
Thanks for reading this post 馃憤
 

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Have you tested the gear position sensor as per workshop manual ?
Opps WP is 93, no gear position sensor. How does the ECM know when trans is in neutral ?
Try asking this question in correct sub forum ie. Water Cooled Gixxers.
Opps again, no ECM.
Still working on it . Page 166 Interlock system checks.
 

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Discussion Starter · #3 ·
Have you tested the gear position sensor as per workshop manual ?
Negatory - the Suzuki manual I have is a PDF of the manufacturers original covering 鈥93 thru 鈥95 and there鈥檚 no mention of testing this sensor. As far as I can determine the sensor only indicates that the box is in neutral, not actually indicating which gear is engaged at any given time.
It strikes me that the bike seems to think that the kickstand is down when I put it into gear hence the immediate motor shutdown.
My Katana does that on occasions when I鈥檝e forgotten to fold the stand it dies immediately.
 

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welp, try jumping both kickstand sensor and clutch, just cuz it works one way doesn't mean it works the other, you already said it dies when you put stand down as it should, so it's working that way as in killing when stand is down and in gear, BUT, its it working the other direction, as in allowing it to run when the stand is up in gear?

apparently not cuz every time you put it in gear and release the clutch it dies right? best way to eliminate either sensor they both work in tandem, the clutch and side stand is to bypass both of them, not sure which year so do you need an inline diode or resistor? dunno, but if you do and that goes bad then it will not run in gear with stand down as its getting faulty data from one of the sensors, but it does run with stand up in neutral cuz those sensors are working..

so teh stand sensor isn't just a kill when in the down position, it also allows the engine to run when up if that makes any sense..

is your bike a model that those two can just be jumped to bypass sensor? manual should reveal that or a member may know this..

I know someo stand sensors have a resistor, so if you just unplug the engine will not run in gear stand up, sensors go faulty, some get gummy and do not release, but you cleaned it, but it could still be behaving in that manner, asif its not being released..

have a known good stand and clutch sensor hanging about? neutral light works right?
 

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Discussion Starter · #5 ·
welp, try jumping both kickstand sensor and clutch, just cuz it works one way doesn't mean it works the other, you already said it dies when you put stand down as it should, so it's working that way as in killing when stand is down and in gear, BUT, its it working the other direction, as in allowing it to run when the stand is up in gear?

apparently not cuz every time you put it in gear and release the clutch it dies right? best way to eliminate either sensor they both work in tandem, the clutch and side stand is to bypass both of them, not sure which year so do you need an inline diode or resistor? dunno, but if you do and that goes bad then it will not run in gear with stand down as its getting faulty data from one of the sensors, but it does run with stand up in neutral cuz those sensors are working..

so teh stand sensor isn't just a kill when in the down position, it also allows the engine to run when up if that makes any sense..

is your bike a model that those two can just be jumped to bypass sensor? manual should reveal that or a member may know this..

I know someo stand sensors have a resistor, so if you just unplug the engine will not run in gear stand up, sensors go faulty, some get gummy and do not release, but you cleaned it, but it could still be behaving in that manner, asif its not being released..

have a known good stand and clutch sensor hanging about? neutral light works right?
Ah my old friend TM, first off this WP is a 鈥93 and secondly it doesn鈥檛 have a clutch interlock, this had previously been bypassed on the loom with the yellow/green wire running directly from the starter to the solenoid,
I鈥檓 just looking at my schematics diagram and it shows a orange/blue wire running from the kickstand relay directly to the Run/Stop switch on RH handlebar, which said switch works fine.
One thing perhaps I should mention but I can鈥檛 see that it has any bearing on this issue is that at this time the clocks/instrument display unit is not yet fitted or connected to the bike with the exception of the neutral indicator light and yes that does light up with ignition on and gearshift in neutral.
I鈥檓 next at the Bike Shed this Friday so I鈥檒l disconnect the kickstand wires and try it with it bypassed, even though it鈥檚 working good enough to start and stop the motor. Incidentally it鈥檚 a heavy duty Yam kickstand off an XVS 1100 and did very few miles, like new, idk 馃槓
I鈥檓 kinda thinking maybe Craigfer鈥檚 on the right track with the actual neutral sensor, although it鈥檚 lighting up the green light and allows the motor to start it maybe seriously fucked up 馃お
 

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I don't have a manual for that bike, but I'd like to see one. Suzuki's logic hasn't changed much so I'll just throw out my 2 cents. You said you know the kickstand switch works fine because as soon as you put it down, it dies. So the switch is working, but upstream is certainly not. Suzuki's logic is an OR. Bike in neutral, or the kickstand up to run. So it should start and run in neutral with the kickstand down. On the newer bikes, the GPS and kickstand switch both feed the safety interlock. Kickstand down breaks the circuit, but neutral keeps it alive. Bike in gear breaks it, but kickstand up keeps it alive. So my guess is that interlock is your issue, but I'd need to see the manual to be sure.
 

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Discussion Starter · #7 ·
I don't have a manual for that bike, but I'd like to see one. Suzuki's logic hasn't changed much so I'll just throw out my 2 cents. You said you know the kickstand switch works fine because as soon as you put it down, it dies. So the switch is working, but upstream is certainly not. Suzuki's logic is an OR. Bike in neutral, or the kickstand up to run. So it should start and run in neutral with the kickstand down. On the newer bikes, the GPS and kickstand switch both feed the safety interlock. Kickstand down breaks the circuit, but neutral keeps it alive. Bike in gear breaks it, but kickstand up keeps it alive. So my guess is that interlock is your issue, but I'd need to see the manual to be sure.
Thanks for your 2 cents bubba, I hear what you鈥檙e saying, and yeah my Katana which is just 2 years newer than the WP will start with kickstand down. If you care to check out the earlier post of Craigfer 63 he has added a PDF link to the relevant manual.
Getting away from it all today meet-up some biker buddies at a Country Pub 馃嵒
 

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Hard to see on that manual, but as I suspected, neutral switch and kickstand switch both feed the kickstand relay. So, my guess is the relay is your issue.
 

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Discussion Starter · #9 ·
Hard to see on that manual, but as I suspected, neutral switch and kickstand switch both feed the kickstand relay. So, my guess is the relay is your issue.
Yeah that鈥檚 right, I did a test swap with a spare kickstand relay I have a couple weeks back and things were still the same, but that鈥檚 not to say that perhaps they鈥檙e both iffy, I鈥檒l have a recheck tomorrow and check 鈥榚m both with the multimeter as per the manual. Keep watching 馃
 

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Discussion Starter · #10 ·
Well guys the problem is gone away!!
Today I was able to engage first gear and pull away and here's how;
Yesterday I took a day off from the Bike Shed and met a couple of good biker buddies in a Bar and one of 'em, Jib who was my former sidecar passenger from our Road Racing days 30 odd years ago told me ' Cut the blue wire between the Gearbox Neutral Sensor and the kickstand diode, then ignore the sensor and connect the wire from the diode to earth - the bike will think it's in neutral all the time and you'll get every gear no wukas!'
After the beer session and I got back home I studied my large full color schematic diagram and I followed the blue wire from the diode up front to the green neutral indicator light, which connects on the other terminal to an orange live wire, so that confirmed that the blue wire must indeed be earth for the light to glow, I'm thinking Jib could just be right on this?!*#+
Thinking about it all last night couldn't wait to get over to the Shed today, got the wire cutters and stripper and a solder filled heat shrink and in ten minutes was sorted, fired the motor, clicked the shift into first, eased out the clutch and Goddam she's moving forward, Yeeehaaaa 馃槀馃憤馃嵒
Did a few short test runs and she's running great, I been 13 months building this Suzuki powered Chop and today it's all been worthwhile, I'm happy as Larry 馃槃馃槃馃槃

To sum up, the neutral indicator green light is now on all the time but no hassle. The neutral sensor can't be all bad because it's been permitting me to start up the motor every time I hit the starter, along with the kickstand diode and relay, which I had previously tested with my Bruv's multitester and knew were OK. Obviously there's something amiss with the sensor for not permitting the motor to keep running when a gear is engaged, but for now I have the bike booked in tomorrow with my regular Bike Shop for the MoT test and then I aim to ride most days when the weather is agreeable until the end of the year, then I'll put the bike away for the winter months and whilst it's laid up I'll investigate the neutral sensor, may just want a good clean or replacing but I'll have time on my hands til Spring.
I very much appreciate the posts from you guys who took the time and trouble to raise topics and offer possible solutions to the problem I had, and I hope that if other Gixxer owners are faced with something similar that this account of it will point them to the cause in no time.
Muchas gracias to y'all 馃檹馃憤
 

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Discussion Starter · #14 ·
Bypass is not a fix. I hope you go back and fix it correctly.
Well Mr Geek the bike passed the Ministry of Transport test on Saturday and is now taxed, insured and on the road - between now and New Year I鈥檓 gonna be donning my leathers and out on the highway ever day that the weather is agreeable, I been stuck in the workshop most of the year building this bike!
I will be laying the bike up the whole of January thru March and I鈥檒l have all the time in the world then to fix or replace anything that needs fixing.
I鈥檓 sure not bothered that there鈥檚 nothing to show me that my transmission is in neutral - how鈥檇 you figure we managed years ago when bikes never had all these gimmicks?馃ぃ
 
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