ok here's my problem and its only happened once. Duc 996 2001 Bip Just had a blast on it and was coming up to traffic ,down 2 gears and into first as I slipped it into 1st with the clutch in the revs went up and up.. Hit kill switch and coasted to side of road. stuck it in neutral started it up and full throttle ?? Kill switch again... ok throttle grip was closing fine and could here the butterflies snapping shut ??? tried again ...full throttle. turned it off sat down had a smoke ( 5 mins) ....Turned it on started no problems??? throttle was working fine again ??? WTF? so a slower steadier ride home so where to start ?? have tried to replicate the situation but nowt? any ideas ?? cheers
Check the cable mate I've seen them fray and they stick in the outer casing. Or the throttle tube take it apart and clean it.
Had a similar thing on my Monster when a tiny piece of gravel had partially jammed open the cable linkage. Only found it by accident whilst investigating and saw it fall out!
The plates on the throttle valve are held on to the spindle by 2 screws (at least they are on a 916) and they can come loose, meaning the plate can move a little preventing it from fitting properly and therefore closing fully, although they should still close and the screws can't/shouldn't fall out as the ends are flared over to prevent this. Mine did this once, as I discovered when trying to set the TPS and the closing was irregular. I doubt they'd allow it to move enough to jam it open though? Otherwise, damaged cable or if you have a foam filter, especially the in-airbox type it could be breaking down and a piece of foam got stuck in the throttle?
I’ve seen on a several occasions is that the linkage can catch on the electrical connectors tied behind the frame rail, just above the battery. Don’t necessarily catch every time either. Worth checking they are well out of the way and securely tied.
ok thanks for the fast replies just came back from me workshop / shed tank off - airbox off linkages all good nothing is near them all free , cable like new (when unclipped its nice and free ) plates on the throttles are tight and working as they should nothing is missing and theres nothing new in the airbox or area .....filter is good all there?? got the tank back on and and 1 of the quick release was a bugger to get back on.. ok put it all back together ....started first press.......been down the road and all is well... And still none the wiser as to why ???? if it was electrical then when I throttled off the valve would have closed so no air = no revs so it aint electrical
I have heard of one of the bolts that holds the spigot under the front of the tank can fall out and then jam the butterfly. Always loctite them in.
Maybe a foreign object that’s now cleared, anyway I’d have another double check of everything if I were you and excercise caution for the next few rides, a stuck throttle nearly put me into oncoming traffic a few years back , an experience never to be forgotten!
Maybe a foreign object was there?? but how and from where foam filter is in very good nick went on last summer and is tight over the trumpets so some steady riding coming up then
Foam filters can get sucked into the trumpets at high revs And jam the butterflies but can go back into shape when the revs die or engine stops
I had something similar with an old Suzuki! It turned out to be an air leak from the air box to the carbs? Might not be related but that bugger did the same thing
A foreign object is most unlikely to come out and impossible to do so if you have a foam filter - it would get 'ingested' by the valves which wouldn't end well. I'd take a serious look at the foam filter as suggested above, there is an awful lot of suction from the intakes that could pull the foam into it. As anyone who has ever put the palm of their hand over one whilst the engine's idling (never mind running at 10k rpm)
That's why my foam filters have a plastic framework inside. Only issue is you can't give them a good ol' squeeze when cleaning.
Dukedesmo quote; “A foreign object is most unlikely to come out and impossible to do so if you have a foam filter - it would get 'ingested' by the valves which wouldn't end well.” An FO in the linkage could drop out and disappear though!, and yes incredible amount of suction as I found out when I put my hand over the throttle body on my wife’s car and asked her to turn it over, nearly broke my bloody fingers!
True but other than a nearby cable or hose you wouldn't expect it. Is it possible that the closing spring on one of the TBs is broken/damaged or somehow binding? Maybe the one on the rear TB?, I know when I set my TPS I leave the rear TB connected to the linkage but wind it out so that the 'rest' position is definitely on the front throttle plate (where the TPS is fitted) but keeping the additional strength of the rear spring in the linkage, otherwise it closes inconsistently on just the front spring making it difficult to get a consistent reading.
