Jerking at low revs/speeds

[Fieldmouse]

Ok gents,

Thank you very much for your ideas and help, I very much appreciate your feedback. I'll have a crack at all the ideas mentioned, and see what happens. I shall post my results. Also, I will test ride after each separate job I tackle, in the hope that when the jerkiness disappears, I'll know what the fix was.

Thanks again all.

[Dusty ST]

I had something like this, dreadful around town on a constant throttle.
Only lasted till I filled up with petrol again so I'm guessing it was a duff/old batch of fuel.
It was the super unleaded from a supermarket, rather regular unleaded, so I assume they don't sell as much.

[Mr gsx1400]

it could be old fuel m8 but my 1400 was much the same at low revs . i fitted a power commander which got rid of the low rev touchyness and allows u to remap

[Irish in Oz]

it could be old fuel m8 but my 1400 was much the same at low revs . i fitted a power commander which got rid of the low rev touchyness and allows u to remap

My 14 is totally stock from new and runs and has always run fine with 100,000 klms on the clock, so if I get problems a power commander will fix it! BTW the rocker cover or anything else has never been off it.

[Kiwifruit]

So you mean thriving on neglect Irish......

[Hooli]

A power commander won't fix it, it'll allow you to dial out the problem. 14s are smooth as standard so jerkyness is a fault.

[Irish in Oz]

So you mean thriving on neglect Irish......

Not from riding, but it's sitting up now for about 18 months so I'm sure when I fire it up in about 9 months time it will come up with every fault code there is.
But I'm not worried because it will be sorted here 

[Hooli]

I fired up a 14 that's sat for about 10 years once. All it needed was the throttles balancing as it was idling on two & it was fine.

It got fresh oil & all that malarky, but it didn't have any issues at all.

[KiwiCol]

So you mean thriving on neglect Irish......

Not from riding, but it's sitting up now for about 18 months so I'm sure when I fire it up in about 9 months time it will come up with every fault code there is.
But I'm not worried because it will be sorted here 

Are you heading back to Aussie in 9 months?   Has it been 18 months since you went back 'home'?  Geez, that went quick.

[Fieldmouse]

Ok fellas, lifted idle from 1000 to 1100, made a considerable difference. I did wait until it reached normal running temperature. Ever so slight jerkiness now. I dropped mine to 1000 as I also didn't like the sound when selecting first gear. The only thing I find now, is there isn't as much engine braking as before. Throttle cable adjustment is fine. Will take tank off and inspect vacuum lines. I have noticed, TPS has never been touched, bike is in mint condition, and only done 17K on clock. Should TPS need to be checked at these relatively low k's ?

[Fieldmouse]

Gidday Fieldmouse, welcome to the forum.  I see you've been a member for a while, but just not posted.

Now, this jerkiness at low speed & light throttle, chain tension comes to mind as does seized links. 
The ECU does not need a re-map for the Yoshi end can, so not much point in putting the bazooka back on.
Check the clutch switch isn't bridged & is working correctly, the ECU runs a different map at start up (richer) maybe yours is stuck on that 'start' map.

There's a wee 'trick' you can use & hear the maps being swapped.  Once warm, sit on it (at ldle) with clutch in and in gear, as if waiting to go from the lights, now just ever so slightly (before the clutch even takes up) let the clutch lever out n watch the rev counter, it should increase by a couple of hundred revs in anticipation of you taking off.  I believe that's the maps swapping in. Once you see it & hear it, it's quite obvious.

Try the things above, I picking chain myself.

Kiwi Col.
Clutch isn't bridged, and I did as you said and tested to see if it switches between maps in anticipation to take off, and it certainly does do that also.

[SheepDog]

Like alot of us I'll address the elephant in the room.

You say your having problems with 'jerking at low revs/speeds' ....
Mate, I went through puberty 40 odd years ago and I never had problems 'jerking at ........

[grog]

Sheepie, was waiting for a reply like yours. 

[Hooli]

I have noticed, TPS has never been touched, bike is in mint condition, and only done 17K on clock. Should TPS need to be checked at these relatively low k's ?

Ideally both TPS should be adjusted every time the throttles are balanced, so yes it's worth doing even on a low mileage bike.

[froudy]

I'd definitely checking throttle body balance and then re calibrating the TPS.

Good luck