Got a bike that refuses to start I had to put a "new" engine in my gsxr it's an sp model that I've kept the cdi from now my problem I'm sure is to do with it unable to pick up the timing from the rotor wheel I have been reading up loads about the later engines needing parts swapped over but foolishly I forgot to rip the old timer off my old engine and can't remember what it looks like is there actually a difference between and early and later model rotor?
Thanks guys great forum

This is Bandit 400 information but I think the same two trigger wheels were used on the GSX-R400.

Is the bike is a 76?

Yes sorry forgot to put that in my post gk76a rl, it also has the single plug CDi the chassis is an sp not sure on the engine dont know how to check if its a normal or sp

SevenThreeSeven wrote:This is Bandit 400 information but I think the same two trigger wheels were used on the GSX-R400.

my engine has the 1st wheel on it I'm guessing that's the stronger one of the two pre 93? i have a kit cdi on the bike 32900-33c50 bb7222 but the engine refuses to fire just seems to be out on its timing but if thats the right rotor wheel for a pre 93 i cant be that

Engine numbers are on this site and show year and model, have a dig about.

With the 12 pin cdis are the pick ups a brown and a blue wire? Ive read you can change these over? Im getting spark at the plugs and fuel in the cyclinders but she just refuses to fire, not even a backfire or puff of smoke, also is there any difference in the sp engine over a non sp or is it just the carbs?

prob not much help, but if the pickup wires are out of phase, the bike won't start. There is info somewhere about which trigger goes with which cdi.

moforockband is 100% correct about this.

The proper name for the bike's "Pickup" is Variable Reluctance Sensor. It is just a permanent magnet that has a continuous wrap of copper wire around it. This wrap of copper wire goes from one end to the other of the permanent magnet and then they lead away into the bike's wiring, eventually to the bike's Ignition Control Box.

When the metal teeth of the trigger wheel pass by the magnet it generates a current in the copper wire winding. The passing of the teeth generate an analog signal, it looks a lot like a sine-wave (but not quite).

The bike's Ignition Control Box takes this signal in and converts it into a digital signal, which is a "square wave" signal (just "on" and "off"). The Ignition Control Box is programmed to look at the Variable Reluctance Sensor's analog signal for a specific "event" which is when the very middle of each trigger wheel tooth passes by the sensor.

Here's the problem when you hook the the Variable Reluctance Sensor wires up to the Ignition Control Box backwards: This reverses the polarity of the signal generated by the Variable Reluctance Sensor. The result is that the specific "event" the Ignition Control Box is looking for will now be generated not when the very middle of each trigger wheel tooth passes the sensor, instead the "event" will be generated by the gap in between the teeth.

This will significantly change the ignition timing (the Ignition Control Box thinks it's doing its normal job but it's working with bad information... garbage in - garbage out).

I've check the engine code it's a k709-10456 trying now to find out what year that is? 92?