K75 funky second gear

[luvaircooled]

I recently bought a '93 K75 with 72K miles on it. It is a great ride, but has a problem when accelerating in second gear. It tends to slip - feels like the clutch violently disengages and engages in spurts. Does anyone have a similar experience? This only happens in second gear, all other gears run fine. Wondering whether this might be a clutch issue or a funky gearbox?

[tsnap]

drivesplines is my guess, from what I have learned on this site.

tom

[Laitch]

It tends to slip - feels like the clutch violently disengages and engages in spurts.

Does this description mean that it lurches when accelerating in second gear or does it actually disengage and you coast?
If you cruise in second gear without increasing revs, does it stay in gear and move smoothly?

[luvaircooled]

It tends to slip - feels like the clutch violently disengages and engages in spurts.

Does this description mean that it lurches when accelerating in second gear or does it actually disengage and you coast?
If you cruise in second gear without increasing revs, does it stay in gear and move smoothly?

It cruises in second fine without accelerating or going uphill, even does ok with very slow and deliberate increasing of revs. on even road or going downhill. When it lurches the engine revs up for a second and then I can feel/hear the drive shaft being engaged in spurts..  I live in the Sierra foothills with lots of fun twisties --- this makes the twisties not so fun  :yes

[Laitch]

. . . this makes the twisties not so fun

I can believe that!
That you describe this condition as being confined to second gear makes the source of the problem seem like the gear assembly in the transmission.

How long have you had the bike and how many miles have you ridden it with and without this symptom?
Have you tried starting off in fourth or fifth gear? If you have, does the engine stall or can you move off without too much trouble?
Have you checked the level of transmission fluid with an accurate gauge?
Have you adjusted the clutch according to standard methods or checked for appropriate free play at the clutch lever?

[TimTyler]

--- this makes the twisties not so fun 

Ride the twisties in 3rd gear.  :riding:

[TrueAce]

Only second gear? Time to open up the transmission. Or really run out first and double shift into third. You can ride a three-speed bike if you change technique. But seriously, think about pulling the trans to look at that second gear. If it were other gears as well, the it would probably be the shaft spline.

[tsnap]

maybe someone was speedshifting it, first to second,  or the splines are only slipping over each other with the second gear torque,  drain the tranny and check for metal

tom

[TrueAce]

Yep, a clutch-less speed shift up would crunch second gear,  But so would a clutch-less stomp down-shift. Time to go inside and play. Do post pics!

[luvaircooled]

Thanks for the suggestions :2thumbup:. It's basically been doing this for the short time I've owned this bike. Checked the gear oil with the tool from the tool kit and it looks to be at the right level and clean. Clutch feels strong and also seems to be in good working order. No telling what the previous owner(s) did with regard to shifting, but it used to be a commuter bike in San Fransisco, so lot's of uphill city riding etc.... After switching out transmissions I'll try and make time to open up the current one and check the inner status of it.

[luvaircooled]

just a quick update. I replaced the transmission over the weekend. Lubed splines and all that good stuff in the process. Put bike together and shifting and riding smoothly again. Planning on taking a look at the inner workings of the old transmission and a possible rebuilt when I have some time in the next couple of weeks.

[Laitch]

 :2thumbup: