This bike is interesting. The owner bought it in for an ECU remap because he realised a Power Commander wouldn’t cure the problems it had; his words “look Mark, if you can fix this I’ll be well happy…” And sure enough it owned some really nasty off-the-bottom splutters.
We started by having a look at the secondary butterflies, as on these earlier GSX-Rs the stepper-motor that drives them can have issues with dried up O-rings hindering its shaft. But no, they were working fine. On the Dyno we went through all the fuelling and ignition modifications that we’d do as standard and removed all the restrictions then took it out on the road.
Oh dear. It was rubbish and we weren’t happy… So we worked a bit harder on the ignition map and eventually ended up with a completely revised setup for the bottom end. And cured the splutter, apart from a very minor glitch – it was like night and day. The owner phoned Gill in the office after riding it a bit and was ecstatic; “it’s a brand new bike!” he reckoned. That’ll do for us.
Nasty bottom end stumble cured via an ECU remap – eventually.
