I've reached the 'pulling my hair out' stage with my surging problems which are approaching the misfire level. They're getting gradually worse and I now suspect that setup isn't the (only) issue. I have:
Set rocker end float
Adjusted valve clearances
Balanced throttles (several times with a twinmax - checked using a carbtune just to be sure the twinmax was working OK)
Run injector cleaner through the system
Tried fuel from different suppliers
Replaced plugs
But the surging/misfire between 2k and 3k rpm on a light throttle is the worst I've ever experienced on an 1100/1150. Bike is a 2002 single spark 1150 with 27k miles on the clock. With more throttle it pulls like a train. Above 3k rpm it's as smooth as a very smooth thing. It idles well too, although pick up from idle is not always smooth - the longer it's been idling (in traffic) the worse the pickup is and the worse it runs/more it surges. When it's cold (up to 3 bars on the temp gauge) there's barely any surging - it's like a different bike. BBPower chip fitted so no CCP issues, but it behaved the same before I fitted the chip so the chip isn't the cause. Throttle cables are seated properly. TPS voltage set to .380 although I've tried it at .360 and .370 too.
I did a bit of investigating last night and found a suspicious lack of paint blobs on the throttle stop screws - they might have been messed with? So I tried checking throttle balance with the air bypass screws closed but it wouldn't idle (too slow). There is a very loud tapping (not ticking) from both throttle bodies at idle, worse from the left (TPS) side - applying light pressure to the cable cam to hold them closed does deaden this noise a bit but I can feel the pulsing through my finger when I do that. I don't remember that being the case on any other bikes I've had. Fuel pump makes an occasional 'bzzzttt' when the bike's idling - can't remember that from other bikes either.
I have vague theories about fuel pressure or incorrect throttle stop adjustment, but the former is probably unlikely since it runs so well at higher revs and the plug colour is spot on. The latter is more likely but would it cause surging/misfiring above idle when the throttle opening is controlled by throttle cable adjustment and not the stop screws? Any ideas what I should be looking at or should I bite the bullet and let someone else have a try? I've never had to resort to outside help before to get one of these bikes running right, but having had some nasty moments in the wet (the surging/misfire can be so bad as to unsettle the rear on wet bends) it's become unbearable.
Any suggestions appreciated, otherwise an inconvenient cross-London trip to SW15 may be on the cards.
Set rocker end float
Adjusted valve clearances
Balanced throttles (several times with a twinmax - checked using a carbtune just to be sure the twinmax was working OK)
Run injector cleaner through the system
Tried fuel from different suppliers
Replaced plugs
But the surging/misfire between 2k and 3k rpm on a light throttle is the worst I've ever experienced on an 1100/1150. Bike is a 2002 single spark 1150 with 27k miles on the clock. With more throttle it pulls like a train. Above 3k rpm it's as smooth as a very smooth thing. It idles well too, although pick up from idle is not always smooth - the longer it's been idling (in traffic) the worse the pickup is and the worse it runs/more it surges. When it's cold (up to 3 bars on the temp gauge) there's barely any surging - it's like a different bike. BBPower chip fitted so no CCP issues, but it behaved the same before I fitted the chip so the chip isn't the cause. Throttle cables are seated properly. TPS voltage set to .380 although I've tried it at .360 and .370 too.
I did a bit of investigating last night and found a suspicious lack of paint blobs on the throttle stop screws - they might have been messed with? So I tried checking throttle balance with the air bypass screws closed but it wouldn't idle (too slow). There is a very loud tapping (not ticking) from both throttle bodies at idle, worse from the left (TPS) side - applying light pressure to the cable cam to hold them closed does deaden this noise a bit but I can feel the pulsing through my finger when I do that. I don't remember that being the case on any other bikes I've had. Fuel pump makes an occasional 'bzzzttt' when the bike's idling - can't remember that from other bikes either.
I have vague theories about fuel pressure or incorrect throttle stop adjustment, but the former is probably unlikely since it runs so well at higher revs and the plug colour is spot on. The latter is more likely but would it cause surging/misfiring above idle when the throttle opening is controlled by throttle cable adjustment and not the stop screws? Any ideas what I should be looking at or should I bite the bullet and let someone else have a try? I've never had to resort to outside help before to get one of these bikes running right, but having had some nasty moments in the wet (the surging/misfire can be so bad as to unsettle the rear on wet bends) it's become unbearable.
Any suggestions appreciated, otherwise an inconvenient cross-London trip to SW15 may be on the cards.
I fitted it at lunch time anyway but, not surprisingly, it made no difference to the way the bike ran on the way home 
