Jerky throttle problem

[discotex]

*Some of the jerkiness is the brief hesitation when the EFI switches modes from "closed loop" to mapped mode. [This is assuming the 600 has "closed loop" mode and O2 sensors like the VFR does]

I'm guessing you mean PAIR? 600rr.net has good info on how to disable it if you can be bothered. I haven't found a need to though.

[vifferman]

I'm guessing you mean PAIR? 600rr.net has good info on how to disable it if you can be bothered. I haven't found a need to though.

Nope.
The PAIR is summat else. Tried disabling that - it dropped the idle heaps, and made a bit of a hole in the power delivery at low-mid range.
My "helpful" comments were made on the basis that I assumed the CBR had a similar EFI system to the VFR, which has a dangerous hesitation when you throttle off (say, for a slow-speed corner) then throttle on again. This is mostly caused by the "closed loop" mode, which is used when the engine is running under constant lowish revs, or small throttle openings, when it uses the information derived from the various sensors including the oxygen sensors in the exhausts, to decide how much fuel to squirt in. When you open the throttle, it switches to 'mapped' mode, which uses the TPS sensor and MAP sensor (and a couple of others) to work out which setting on the EFI maps to use. The transition from closed loop to mapped mode takes a brief time, which is too long.
But (however!) for many bikes, EFI is much more 'lightswitch' (on/off) than carbs are, and does take some getting used to, regardless of whether the EFI system is mental or not.

Personally, I test rode a CBR600 before/after riding my VFR, and found the throttle response was OK, so I'd guess that most of the "jerky throttle problem" alluded to is just part of the learning curve for switching from a carbed 250 (with somewhat laggy response) to the more instantaneous response of a modern EFI'd 600 sports machine.

[325rocket]

The transition from closed loop to mapped mode takes a brief time, which is too long.
But (however!) for many bikes, EFI is much more 'lightswitch' (on/off) than carbs are, and does take some getting used to, regardless of whether the EFI system is mental or not.

Personally, I test rode a CBR600 before/after riding my VFR, and found the throttle response was OK, so I'd guess that most of the "jerky throttle problem" alluded to is just part of the learning curve for switching from a carbed 250 (with somewhat laggy response) to the more instantaneous response of a modern EFI'd 600 sports machine.

i had a feeling it was the closed loop - mapped transition. i guess i will get used to it in time.
thanks for the replies

[vifferman]

i had a feeling it was the closed loop - mapped transition. i guess i will get used to it in time.
thanks for the replies

You should at least get the throttle cable slack taken out. The manual says it's supposed to be there, but it adds to the hesitation somewhat.
The best thing to do is ride, ride, ride! Go and practice some slowish speed turns, etc., using the back brake as a rudder, and when you're in slow or start/stop traffic or otherwise going slow, make a point of using the clutch rather than the throttle to regulate your speed. You'll see what I mean when you try it.

[discotex]

Nope.
The PAIR is summat else. Tried disabling that - it dropped the idle heaps, and made a bit of a hole in the power delivery at low-mid range.

Ahh right. Quite a complex fueling system. I haven't read through the service manual properly yet to get my head around it all.

[slimjim]

mate its a totally new ride..and you'll find things hugely different forsure..and won't touch your cable just yet...would say getting use to it been the first thing...an ya's worries will go..and don't roll off completely...enjoy the bigger grunt..

[captain_andrey]

Had the same problem with I first got the 600. But it all went away as I got more precise with the throttle. On a 250 the margin for error was huge so I never learned to roll on the throttle smoothly.
What I do is make sure I am in 2nd, put some pressure on the rear break and slip the clutch when I need to go real slow.
So just go riding, you will pick it up real fast.
After completing the 1000k cruise on saturday, I finally feel at one with the bike. 30k of gravel really helped with the confidence, esp once I got up to 100km/h on the loose stuff.