R6 Throttle - Coldstart issue?

[Craigg]

So fitted the R6 throttle at the weekend, all went smoothly and ran perfectly on the way home, really liking the new throttle action.

however yesterday morning riding out the street on my way to work it cut out. after that it ran perfect.
Same thing when heading home from work, when it dropped back to idle (after just pulling away) it cut out, restarted it and it was fine for the rest of the way home.
same again this morning (cut out once, then ran fine).

not sure what the issue is, its obviously something to do with the throttle, but i didn't make any changes to the throttle cables at the throttle bodies, i only adjusted the in-line screws under the handle bars to allow me to get the new throttle on.

so i guess i'm asking, how does the throttle adjustment work on the handle bar end? as clearly i have got something wrong. from what i can see, the throttle is sitting on the stop, and its reaching WOT when twisted.

just a bit frustrating that i cant really mess about with it, because after the bike has some temperature in it, it runs fine.

it doesn't do it when there is no load either, if you fire the bike up cold, and blip the throttle, its fine, its only when moving.

[Redmist]

Its possible (perhaps unlikely seeing as it only happens when cold) that you've knocked something electrical when doing the change, the cut out switch is on that side so double check the wires are good and that the switch is still operating cleanly.

[Craigg]

so I've worked out whats causing it, when the throttle is closed, if you grip it and roll it forward (ie trying to close it further) it does actually close more, drops the revs and stalls the bike.

not had a proper chance to mess about with it as yet, but i don't know if its my resetting of the cable tensioners that's caused this, or if its something to do with the R6 throttle.

is there a "stop" inside the grip housing? or does it just rely on the stops on the throttle bodies, via the cables?

[DarrenSV650S]

Did you modify the new throttle tube? Not sure what bike you have, but on my pointy I had to cut away some of the plastic where the cables attach. There is a picture guide somewhere that shows you where to cut.

Mine was always a little dodgy though and I think eventually I went back to stock

[Bibio]

so I've worked out whats causing it, when the throttle is closed, if you grip it and roll it forward (ie trying to close it further) it does actually close more, drops the revs and stalls the bike.


you have just answered your question.

what is happening is that the close throttle cable is acting as your tickover adjuster instead of the actual tick over adjuster. you need to loosen off the throttle cables so there is play, adjust your tickover till it sits around 13-1400 RPM when hot then adjust the play in the throttle cables. when adjusting the play in the throttle cables you must turn the bars from lock to lock so there is no rising of the revs.

[Craigg]

Did you modify the new throttle tube? Not sure what bike you have, but on my pointy I had to cut away some of the plastic where the cables attach. There is a picture guide somewhere that shows you where to cut.

Mine was always a little dodgy though and I think eventually I went back to stock

i didnt modify the throttle tube, i have a K5 Naked, from what i read on SVrider, its only S models that need the tube cut. was a bit fiddly getting the cables on, nothing some choice curse words didnt sort out though :O

will get everything loose when i get home tonight, see if i can sort it out :)

[tom_e]

I'm pretty sure all pointys need it trimming it's the curvy that doesn't

http://forums.sv650.org/showthread.php?t=83740&page=2

[Craigg]

http://www.svrider.com/forum/showthread.php?t=50611&highlight=throttle+tube

is the thread i was going off, its getting full throttle (at the throttle body) so i don't think the grip is hitting anything

[Bibio]

i tried messing with an R6 tube on the Sport housing and the naked housing but it was a PITA so never took it any further. i dont have any problem twisting my wrist on the OEM one for WOT.

yes the naked and sport tubes are different.

[Craigg]

so adjusted the throttle cables and idle last night after work, idle at ~1300 (when hot) and there was no forward movement from the throttle (so i couldn't roll it forward to "close" it more)

this morning, from cold thought i would try it just to be sure id fixed it, and sure enough, rolling it forward closed it more and dropped the rev's right down (didn't stall mind, but was close)

any ideas why the travel is there when cold, but not when hot?

[Bibio]

your using more force closing the throttle when riding the bike than you would with it sitting stationary. loosen off the 'close' cable a tad more and adjust the tickover accordingly.

whats happening is exactly the problem i had apart from the low revs. when you close the throttle the new tube is not the correct shape to hit the stops inside the housing its close but not enough. when you ride the bike you use more force so where the new throttle tube would otherwise 'just' rest on the stop it continues on past.

to test this when the bike is sitting stationary try forcing the throttle forward, i bet it 'clicks'.

[AlexAdams]

I'd be almost certain that your cold idle speed is not adjusted correctly. What is the rpm when you start the bike from cold at what is the approx ambient temperature at this time?

See this thread here where I found the whole TB to be setup incorrectly on mine, I also listed the expected RPM's at cold idle temperatures..

http://forums.sv650.org/showthread.php?t=223306

[Craigg]

your using more force closing the throttle when riding the bike than you would with it sitting stationary. loosen off the 'close' cable a tad more and adjust the tickover accordingly.

whats happening is exactly the problem i had apart from the low revs. when you close the throttle the new tube is not the correct shape to hit the stops inside the housing its close but not enough. when you ride the bike you use more force so where the new throttle tube would otherwise 'just' rest on the stop it continues on past.

to test this when the bike is sitting stationary try forcing the throttle forward, i bet it 'clicks'.

i don't get any appreciable click when i'm forcing the throttle forward.

its got a lot better since i re-adjusted everything, but its probably still needs a bit of fine tuning, issue is i have run out of adjustment at the grip end of the cable, and i don't want to be messing around at the other end too much for fear of messing everything up!

[Bibio]

well your not going to solve it unless you can get more slack in the cable which means you will have to loosen off the throttlebody end.