Hello all, I have a 2013 with 20K miles. So here is my dilemma. I can come out the hole in 1st and 2nd gear no problems. As soon as 3rd gear starts it seems to slip, like the chain is coming off the sprocket. I have checked the clutch, replaced the springs, and changed the oil. I have asked around and most think it may be the clutch but the clutch is good. It only happens in 3rd gear. It feels like the chain is skipping, that is the feel. If I am cruising in 3rd it is fine but as soon as I goose it it will jump a few times and then finally get after it. Does this sound like the 3rd gear internals are shot or is there somewhere else I should be looking at? This is where I need your help. It doesnt wind out like I would think would happen if the clutch was slipping and it only does it under load in 3rd gear, no other gear.

I can't say for sure, but I have been through the worn gear dog issue, which was a different bike and 2nd. It would slip out and back into gear, almost like during acceleration I just yanked the clutch, and 2nd would reengage as revs came back down. It progressively got worse. With it slipping out of gear, it bent a shift fork and also caused some excessive wear. It's difficult to say 100% if I had stopped riding it the very first time it happened if the repairs would've been different (100% required pulling engine and splitting case on that bike).

I've also experienced a worn clutch, and that sensation is similar but not the same. Worn clutch slipping is not nearly as instantaneous as when the gear dogs disengage.

Doing the work myself, I replaced all the gears in the transmission based on an actual mechanics recommendation and the shift fork. His basis was precautionary so that it wouldn't have to be done again just in case other gears were nearing that same wear level. I'm not 100% certain that's necessary, but minimally it'll be 2 gears that will need replaced and maybe other parts if they are worn or damaged.

Need:
3rd-13262C
5th-13262I
ring-92033 Qt. 1
race-92048
needle-92046A
bushing-92139

https://www.ronayers.com/oemparts/a/kaw/50aa36ebf8700226a41461e9/transmission

Fork-13140A

https://www.ronayers.com/oemparts/a/kaw/50aa36ecf8700226a41461ea/gear-change-drum-shift-fork-s

The above is minimum parts. I did not include side gaskets, sump gasket, etc.

Might want to freshen up with rubber seals like the output shaft. Probably will last if not changed but it's more a fix it before it leaks, than fix when it leaks.

I'd drop the sump cover once the mufflers are removed. This will have the shavings at the bottom of the pan, rather than flip it upside down to split the case and they fall in, etc.

Any gear under load would jump chain, or slip at the clutch. It narrows down to 3rd chewing away both dog ends and slot cuts on the opposite gear. While in there, might as well check for any marks on the other forks, dogs worn at 2nd, etc.