Hi SuperSport Friends Having finally gotten my 750 to run pretty well, all things considered, I have recently been getting some odd behaviour from it. Background: the engine has been molested at some time in its past - don't ask me what's been done, no idea as the lump was second-hand. It currently has a PCIII that was necessary to sort the fuelling and until recently, has been running very well indeed. I have been having problems with the ignition pickup sensor - the three-wire block connector from loom to the crank sensor needs regular TLC as it has picked up some corrosion in the past, and is not happy. I need to crack it open and clean it out on a regular basis. Symptoms, which have all suddenly sprung up at once: 1. Lumpy/jerky up until about 3000rpm, needs a lot of clutch love in 1st & 2nd gear. 2. Intermittent reluctance to rev above 6000rpm in 2nd, 3rd and 4th gear. Usually at some point in the ride, the engine will "break through" and rev normally in these gears. 3. Pronounced reluctance to rev above 6000rpm in 5th, only rarely ever "breaking through". In order to go faster, I have to drop down from 5th to 4th, rev up to say 8000rpm and kick it up to 5th. The bike will then begin to slow but, assuming the throttle is wide open at that point, I can begin to close the throttle and the bike will speed up. Huh? I suspect that the answer may be a TPS reset and in addition, the CPS/ignition pickup sensor itself might need attention. To recap, all was well for several months with the current set-up. It's possible the PCIII has started to malfunction but removing it from the equation, even on a temporary basis, isn't really an option. First of all, I want to see whether anyone can say, "Well duh, it's obviously this thing". Thanks, guys!
refusing to rev is it still running on 2 cylinders or dropping onto 1 wonder if there is a fuel blockage in the injectors had similar fault with mine turned out to be main bearings failing giving play causing erratic timing at the pick up when speaking to the guys at italia moto I explained symptoms they said this straight away when checked sure enough so might be a common problem but that's was just mine could be something really simple can you get a diagnostic set up on it at all
The problem is at its worst when the bike is in 5th. I would have thought that main bearing or injectors issues would be across the board but perhaps not. Hope it isn't bearings As for diagnostics, I know how to put petrol in it. Beyond that, there's a competency shortfall
dude i know you can. have a look they can tell you plenty. low fuel pressure/blocked injectors. ignition missfire. have quick look. if you have a multy meter check the resistance between electrode and threaded part.
Fuel filter crapped up? Also pipes inside tank not sound would cause that. With a fairly full tank watch from filler to see if air bubbles come up when pump primes. Ignore swirling from return thats normal, but bubbles indicate pipe loose connection or split hose.
hmm, how much do you love it? - besides treating the bike to a new timing sensor and usual filter/hose check, the TPS* does sound favorite here but don't know your bike/system that well - the gaining speed by reducing throttle is certainly one symptom of* failing/becoming erratic. I'm not sure if I have any left now and probably wrong spec anyway - Magnetti Marelli/Weber system? black body/red body? Hopefully a specifically SSie expert will be along soon.
I tuned tps by ear on my ie. Had it checked later and it was spot on. I gunned the motor 1000-3000 rpm and swiveld tps l+r until it picked up clean then nipped up the screws. Tps out would make run rough low down and on neutral throttle. Really out causes popping/missing.
I forgot - it's popping like a good 'un at moment. This is looking TPS-y now. Is there a suitable video or set of idiot-proof instructions for fiddling with TPS available? I've never done this before. Thanks
setting up the TPS by engine sound and engine pick up is not out the question and certainly not as scary as some would have you believe. If you can get hold of a picture of the TPS or even better still a part number I will have a rummage and see what I have left as I used to have several systems from various cars. TPS failure can include going completely dead/idle only/coughing and banging poor pick-up or erratic running through part or all of the rev range.
ahh just thought check earth wire on the cdi for corrosion have been told that can cause running problems actually check all earth wires lol persevere and you will be glad you did
Hmm, earth wire to battery ... previously the bike fired up almost before you hit the starter button but recently, it's hesitated a little. Not 999S faffing-and-fussing-level hesitated, but hesitant by it's own standards. OK, basic checks ...
good thought Johnboy - you just reminded me of at least one person telling me of this on an ie* and coughing and banging were the symptoms *faulty/loose earth on CDI/ECU whatever it's referred to as or possibly both - need to look at a circuit :smile:
Tps is LHS between cylinders. Just check its tight or hasnt broken. Once you move it you might have an extra problem.
Thank you Keith - damn, got nothing like it if that is how std unit looks - cycleworks - is that aftermarket type though? Mine look more like this
A dying regulator would cause rough running too. Have you got 13.5ish volts at the battery motor running 2000rpm.
Think original has magneti marelli on it but identical. ie has to have slotted screw hole type as they cant be adjusted by laptop.
Mmmm, I wonder where you can get the California Cycleworks ones :Hilarious: they are the improved ones so I am led to believe - in fact I have sold a few to UK Ducati dealers over the last 2 months :Facepalm:
