I've got a few single spark motronics 2000 and 2001 , you could try it and see if it makes a difference..
I guess ECU failure is pretty much unheard of in your experience? Well, total failure anyway.
I've got a few single spark motronics 2000 and 2001 , you could try it and see if it makes a difference..
There's more....
After half an hour or so of riding, particularly in traffic, below about 3,500rpm as you accelerate (gently or not), the power comes in in unpredictable steps until you're over 3.5k rpm at which point it all smooths out and runs beautifully. It's this unpredictability that made me switch to using a different bike - on wet roads covered in leaves the steps in power were enough to unsettle the bike (with the wife on the back) and lead to a few unpleasant 'clenching' moments on bends until the rear regained grip
Really it's like the light throttle problem 'spreading' and getting more pronounced - have you experienced that too? I guess if you don't ride a lot in traffic you might not have.
Sproggy - are you sure you're not riding my bike when I'm not looking?
I don't know exactly what I changed that stopped that particular habit but something has thank god. I changed the TPS and the Halls around then (which had a load of the Sahara still in it but I don't think that should have caused the fault) It hasn't done it badly for a while now even though it does it a little bit occasionally, but I think that is more down to the enduring trailing/light throttle problem + my continuous obsessing looking for the slightest hiccup.
See what your mate says Sproggy - you never know your luck![]()

Thinking about this, the fact that changing your TPS and hall sensors cured the lumpy throttle response suggests to me that it was likely to be the TPS at fault. ..
TPS would have registered a fault even if it was ok at the time, and it would have flagged up when i plugged in the diagnostic into monkeyboys bike. It showed no faults.
I mean, could returning an erratic (but within tolerance) voltage still happen without registering as a fault? ..


Ah. OK, point taken![]()
and that smoothed it out. I went to Wales and it was better on the way up so I put it back to Neils and it immediately started acting like a beeeeeeatch again so I put it back to my original and it was better but not perfect. So maps definately make a big difference to mine. Having said all that - I'm back on Neils at the moment because the high speed running and pickup are much better.The thing that did show up I seem to remember was that the lamda wasn't showing what Neil expected. It should be like a nice smooth sign wave but it looked clipped on the top. We've both got non OE NGK lamdas haven't we? If I can remember where I've thrown it, I might put the original one back on and see what that does.
The thing is, and I don't know whether this is common for all GSs, but blipping the throttle is often fluffy during downchanges. Not from high speed, just the little blips coming up to junctions and alike - it's not chrisp and immediate like it used to be on my S.... like it's got a heavy flywheel or something.
I just have to stop obsessing about this and try to forget about it.

An update on this.
Any progress on yours, monkeyboy?
Did the job, then went up to Huntingdon to collect and fit some Ard panniers, and on the way up the bike was farting around again. Went over to Kettering to get horizontal then to the NEC - bike running like shit now. Came back to Southampton and its running rough again...and... I think it's started its grabby throttle again sometimes. Ride to and from work today and it's definately getting worse and worse. Now its often bad at anything up to 60 and tickover doesn't sound right either.







Guys, there are now three of you suffering a similar fault on similar age bikes. Yet from scooting through all the threads again none of you has tried a different ECU yet.
Surely one of you, or all three as a group, need to source a replacement one and try it. Between you all, you've tried just about every other component, it must be long overdue to try the ecu, the whole thing. Its mentioned somewhere about a dry joint or something, and in my mind thats highly likely, as it's one thing that can cause such intermittent faults. I find the same when dealing with PCB's on gas boilers at work, intermittent faults are more often than not caused by dry joints.
I also believe that manufacturers always let QC drop as a component reaches the end of its normal production life, so the fact that yours are all last of the single spark models doesn't surprise me.
If you know earlier models use the same ecu, as has been mentioned, I'd give Motoworks/bins or sherlocks a try for an 00-01 one.