Does it shift smoothly if you don't use clutch?

 

Never actually tried shifting without the clutch, i guess i can try learning it later but i don't think it should normally do it in either scenario, with or without clutch.

 

Sounds like the gears that make up 5th gear are not engaging completely all the time. Not a normal thing.
There are about four most probable causes a guy thinks of when that happens. Although anything could happen...

The shift linkage could be hanging up when going into top gear. Could be inside the engine or outside of it. Outside linkage is more likely if it is a problem with linkage.

If there is considerable wear on the slots and dogs of the gears that could also cause partial gear engagement some of the time. (But normally they 'jump in/out' of gear more than not with worn dogs and slots ).

If you have a bent shift fork that will keep a gear from meshing fully with it's mate.

Engine oil could even be a cause. If the oil is badly contaminated, old and thick or the wrong type entirely that could make it to do as you describe. And it could effect 5th gear only. Stranger things can and do happen.

When the 'load' on the trans is reduced or altered somehow (pull clutch lever, bump throttle, on throttle/off throttle, etc.) that can then allow the gears to sort of right themselves and completely engage.

If not sure of the engine oil I would try New, Motorcycle Spec engine oil first.. Maybe you'll be lucky and won't have to split the engine case cause two of my guesses (shift fork or gears) will require total engine disassembly for repair. (It's a single cylinder engine, right?)

S F

 

Maybe it is worth mentioning the oil sat there for 3 years but during that duration it only had 1200km put on it or less. I changed the oil for a fresh one when i bought it, and when it was first serviced it had the oil changed again (after like 300km). But again i don't remember the bike having this issue in the first 1000km of my ownership.

 

The oil has around 1300km on it, 10w30 as manual says, motul 7100. The bike only has around 25000km and it'd make sense the 5th gear is the least stressed gear as i can't think of any way one could damage it. There is no linkage afsik, the shift lever is connected directly to a rod that goes inside the engine. Once it jerks in nothing happens, outside of this flaw it runs perfectly fine. I don't remember this being an issue early when i bought the bike (i only put around 1700km on it total), so i am quite confused and hope it won't require the engine to be taken apart, that'd be very expensive. But yes its a single cylinder. The only thing i can think of is moving the shift lever a few teeth down so its easier to shift up, if by any chance its just wrong shifting even though i highly doubt it. Yes its a single cylinder, 5 gears total.

 

Oil should be changed based on mileage or yearly, whichever comes 1st.

How much slack do you have in cable before it actually starts pulling on clutch arm?

Post photo of shift-lever and foot-peg. Maybe angle is making it more difficult to move shift-lever.

 

The oil is fresh, less than 2 months, around, 1500km on it total. The shift lever is connected directly to a rod, so there is no linkage. (Older pic).
The only thing i can do is remove the clutch cover on right but there is not much to see and i doubt i'd spot anything out of the ordinary. One thing i'll do as an experiment is lower the gear shifter so its easier to upshift. But i doubt it'll make a difference with this issue.

 

Yeah, try rotating shift-lever down one spline.

I'm also wonder if clutch cable is too loose and not disengaging clutch fully.
Might want to tighten cable (unscrew from lever perch) adjuster 1 full turn and see if that changes behavior.

 

Yeah, try rotating shift-lever down one spline.

I'm also wonder if clutch cable is too loose and not disengaging clutch fully.
Might want to tighten adjuster 1 full turn and see if that changes behavior.

Is there any way to test if the clutch could be an issue? I did tighten it so it engaged a little earlier but ive never noticed it trying to go forward or the rpm going down even the tiniest bit when shifting to 1st.

 

Need to test under identical conditions. Get up to speed and shift to 5th gear. Is problem still present?

 

Yeah that doesn’t sound normal man. First thing I’d do is check the gear lever and linkage to make sure nothing’s loose or stuck. Even small play can mess with the shift. If that’s all good, maybe change the oil, old or thick oil can make gears act weird. If it still does it after that, then it might be something inside the gearbox.

 

The oil has about 1600km on it.
The shifter is linked Directly to the rod so there is no linkage. I moved the lever lower to make it easier to upshift. I havent tested it properly yet, this weekend i plan on testing it but i dont think it'll solve it honestly

 

You’re checking all the right things. To test for clutch drag, start the bike, pull the clutch in fully, and shift into first. If the bike slightly moves forward, there’s some drag. You can also try spinning the rear wheel by hand with the engine off, in gear, and clutch pulled in, if it’s hard to turn, that’s another sign. If everything feels smooth and there’s no creep, the clutch is likely fine. Your ride test this weekend should give you a better idea, so just pay attention to any sound or feel changes.