I have a couple of Kawasakis a 2013 Versys 650 and a 2019 KLX250, both of these bike, I often miss the 1st-2nd shift. I've never had this particular issue with the other motorcycles I've owned. I understand the jump from 1st to 2nd may involve a greater jump as you are passing by the neutral position. Also my KLX250 has been jumping out of 6th gear in particular. I am the second owner and will be tearing down the shift mechanism as I have read that damage from a fall may have bent the internal shift locater pin, and I want to check it out. Also it may bethat my ankle will not permit me to lift the shifter far enough. I have reset the shifter one tooth down on the splined shaft and it seems to be better. So just trying to figure out whether the problem is with the screw loose in the driver's seat, or a mechanical issue?

 

I'd try lowering the shifter first to see if it works. I know some riders have gone with the XR650L aftermarket shifter, but usually to deal with larger foot sizes.

 

The gap is not longer between 1st and 2nd gear, neutral is just a spot in between as you can see on the shift star.

 

The shift move isn't longer from the bottom of the detent to the next detent bottom, but is "longer" to get past the "top" of the detent peak.

If you look, the peak of the down ramp of the star is half way between the valleys of the detent on 2-3, 3-4, 4-5, and 5-6. But not on the 1-2 ridge, where it is truncated with the neutral detent, creating two peaks, one about 1/4 and the other about 3/4 the distance between the detents, so it is much easier to miss the 1-2 shift if it is under-shifted. When slightly undershifted, the star doesn't quite move far enough get past the peak going into 2nd and will end up sliding back and down into neutral. The drum rotation isn't long enough to get past the second peak.. That is the problem on a 1-2 shift hitting neutral. The ridge of the detent requires at least a 3/4 rotation from detent to detent, where the other five will only require a bit over 1/2 the rotation. They will hit on the ramp down, where the 1-2 shift may hit on the back side of the neutral down ramp and end up in neutral. .

So the shift from 1-2 is technically longer in necessary rotation to hit the shift detent since the second peak is further along in the rotation. Now on popping out of sixth, I will say this probably points out that the OP is not rotating the shifter drum far enough, they are not moving the lever full travel. I have short feet and have to be careful about this myself. Virtually all missed gears on a good gear box are due to not moving the lever far enough to get past the star peak far enough to hit the down side of the ramp and have it help engage the next gear. To the OP start moving your foot further on the shift, even if it means lifting your foot off the peg a bit or positioning your heel on the peg to make the shift. I often have my heel on the foot peg when shifting, because I have a size 7 foot - about two sizes below average male foot size.

 

I stuck a 1/2 inch PVC pipe coupling onto my shifter with silicone for easier more reliable up and down shifing.

 

How is that easier when now the distance from top to bottom of the shift lever is longer, so you have to swing your ankle up up the top of the shifter even more to downshift...?

 

It's easier for me because I don't have to press the lever down as far,
just as it's easier for me because I don't have to lift the lever as far.
This works great for me because my feet are small and I don't wear boots..

 

Thank you, I understand what you are saying. But I have been riding motorcycles for over 50 years, for the most part Yamahas offroad mostly. At 77 I had to transition to road bikes and my shoe size although 10.5 and my ankle movement isn't what it was. That being said, I've never experienced this many missed shifts. Not sure about my Versys, but the shift mechanism for the KLX is on the shifter side, which surprised me, because all the other bikes I've been associated with have it on the clutch side, the shaft extending through the engine to the other side. I would think this provides a more stable and durable design. I have been experimenting shifting without using the clutch, which is common practice for riding offroad, on the KLX and it feels like I am getting a more positive shift. Appreciate your response.

 

That doesn't make sense. You're still pressing or lifting the lever the same distance as you were before. The diameter of the lever is larger but you didn't mechanically change the amount of travel required to change gears like a short shifter in a car. Adjusting the height of the lever via the splines would have the same effect.

 

It's not about length of travel travel.
It's about where my foot is after the lever has been moved.
Below, it's not as high and above it's not as low.
The larger lever eliminated occasionally missed 1-2 shifts.
It's ok if you don't understand.