GSXR Clutch ByPass
April 18th, 2010I got this off the WERA BBS from user m0rtal1ty. It will help you when you try and bypass the clutch switch and instead your bike goes into limp mode. Here are the detailed instructions with pictures.
Writeup: GSXR 600 clutch switch bypass relay mod w/ pics
I finished up the clutch switch bypass mod on a K6 GSXR with great success. This mod is an alternative to putting a switch on or bridging the clutch wires for starting the bike and also avoiding the limp map the ECU uses under a continuously disengaged clutch scenario. This mod is very easy to follow with some basic understanding of electronics. At any rate I’ll try to make this tutorial fairly clear and comprehensive and I apologize in advance for the length.I originally did this mod out of necessity; I sold my turn signal control pod on my new-to-me 06 GSXR 600 thinking it wasn’t necessary for starting the bike. It was. None of the other bikes I’ve ever had needed the clutch disengaged for starting in neutral… but whatever. Here’s whats involved:- 12v automotive relay, RadioShack part #275-001 or similar
- A few female quick disconnect terminals.
- Soldering iron or some splice connectors.
- Electrical tape and some wire.
- K6 GSXR or bike with similar problem.
As said earlier I’ve done this on an ‘06 GSXR but I imagine other bikes are similar if not identical.
Start by removing the turn signal control pod and selling it on eBay. Was already ahead of myself there. You could get about $40 for it but hurry up before everyone else does this mod and floods eBay with used K6 gixxer control pods. As there’s no need for it on a race-only bike you can use that space for something like a switch, camera mount, or a GPS if you get lost during your race. Anyways.. The rest of the work we’re going to do is under the seat.
Next, unplug both of the main battery cables and remove the starter relay and wiring from its mount. Go ahead and unplug the black wiring connector from the relay and make a cut down its wiring sheath to expose the 4 wires; two red wires for power, a yellow/green one from the start switch, and a black/yellow wire from the clutch switch. Both of these yellow wires also plug into the ECU so it knows whats going on with each of these.
What we’re going to do next is trick the ECU into thinking the clutch is disengaged every time you push the start button. *Caution: This will also make the bike start when its in gear. That could make a very embarrassing or very hilarious situation in the paddock depending on which side of the bike you’re on. Mmmkay?
We need to tap into the Y/G and B/Y wires since we’ll be plugging those into our RadioShack relay. You can use a number of types of splicing connectors but considering the space and that we want this to work 100% of the time I decided to solder the wires on. Cut some of the jacket off of both the Y/G and B/Y wires to expose the copper wire, but don’t cut the wire. Just like in the movie Speed with Sandra Bullock and Neo. Then solder your two pieces of wire on (white wire in my case) and wrap it tight in electrical tape then crimp your disconnects on. I drew a black line on one indicating it was the clutch wire. We haven’t got to this part yet but the black wires with blue disconnects is the ground wire I put together.
We’ll continue with the B/Y clutch wire next. We want to plug this into our RadioShack relay. Since this is the wire we want to be grounded when the starter is pushed we’ll plug it into the 87 terminal on the relay. The other end of this circuit, 30, will be grounded to the battery all the time. If you have a double throw relay you can ignore the additional terminal 87a.
The remaining Y/G wire will be plugged into the 85 terminal and the other end, 86, grounded to the battery as well but it should also work in reverse although it didn’t with mine for some reason. What will happen is when the starter button is pushed and +12V runs through the Y/G starter wire it will activate the relay and bridge the B/Y clutch wire to ground and then release it when the push starter button is depressed and the starter wire deactivates. If you’re in doubt on which wire is the starter switch-connected wire you can start to poke around with a multimeter. With the ignition ‘on’ but the engine switch set to ‘off’ look for a wire that has about +3v standby which then outputs +12v when the starter button is depressed.
Make sure both ground terminals are grounded to the batteries’ negative terminal. Below is a cable I made with a ring terminal on the battery end and two female quick disconnects on the relay end. I soldered the additional wire in place for a rugged ‘Y’ connection to both grounds on the relay. You can do this a variety of different ways though.
Try to start the bike and see if it works. After it does go ahead and stash your relay in the subframe out of the way. I zip tied mine to a wiring harness in the tail for some shock absorption so it will continue to work after I inevitably crash on the track I did all this work for.
Now put the new clipon space to use. I put a start/run switch from a CBR on mine to power a data acquisition setup and I also have a free momentary switch for something else.. like a horn that plays dixie. Or not.
This setup either works or it doesn’t; check your wiring if it doesn’t start or if the relay makes a buzzing noise. In other words… if the bike starts up and promptly proceeds to run away into the nearest tree, parked car, pack of school children or gaggle of church nuns then you’ve done something wrong. If you’re reading this now and its actually worked then be sure to report in with any comments or petitions for addendums or any funny stories about the bike running away into arbitrary things the first time you started it and forgot it was in gear.
m0rtal1ty
