I have looked through old posts and found a couple answers, but not quite what I was looking for. My transmission routinely jumps out of second when shifted at high rpm ( over 10,000) without using the clutch, and almost as frequently out of third when shifting at high rpm without the clutch. Yesterday it jumped out of third and into first, first time it did that. Jumped the rpms to probably over 20,000 for a second, caused the rear tire to skid and almost dumped the bike. Never did a 3-1 before, normally 2-1 2-N 3-2 or 3-N(major gear crunching sounds on this one). I am positive I was in second prior to up shifting, and after it jumped to first I shifted up and the neutral light came on.

Now my question. I have seen the upgraded shift star / spring kit that claims to eliminate missed shifts, does this sound like the issue I am having or is my problem more serious? I am a decent mechanic, but these transmissions are a little different than anything I diagnose. Help would b good, preferably input from people who have had and cured similar issues.

 

It's a little too late for that shift kit my friend. You've rounded off those nice sharp edges of the "windows" of your 2nd gear and done the same to the dogs of corresponding male gear (5th or 6th, can't remember offhand, think it's 6th). Also need to measure thickness of shift forks where they engage gears, check straightness of shift fork shaft, and check the grooves in your shift drum. If you're lucky, you can get by with just replacing 2 gears first mentioned. If you want to continue clutchless shifting, I suggest sending both shafts somewhere and having gears undercut. You'll get better engagement of the gears and tranny will last you longer. APE, FastByGast and few others do great work. Grab a manual and study the procedure, it's pretty simple job if you're mechanically inclined. And it'll save you a small fortune over having a shop do it.

 

wow attempting your own undercuts? Can you point me toward some walkthrus on that? I'm pretty sure I need some work on my 2nd gear as well.

 

I think he said you can remove and install your gears. You need to send the gears out to have the undercutting done. You'll need some manuals to do the work. They can be bought online for about $20.

 

Well, that is depressing. I am not looking to tear the engine apart on this bike, I bought it because it was cheap. This problem has existed since I bought the bike this spring, but has got only slightly worse since then. Since this is almost never a problem when using the clutch, or shifting below 10,000rpm, I think I will just live with it until I can buy an F4i.

 

I re-read your original post. A shift kit might work for you. Another guy had issues with bouncing 1 to 2 past his neutral point. A weak/cracked spring was his culprit. Open your side case up and look at the shifter detent/spring and see if there is an issue. Cheaper and easier than opening up the bike. One word, the shifter kits use a lot stronger spring than the stock setup. You will feel it at the lever.

 

Well, my current spring is most probably weak. I can accidnetly bump to a new gear without even knowing i have touched the shifter, so a stronger spring would be VERY welcome. And like i say, it does not happen when I use the clutch only clutchless shifting.

I put the bike on the swingarm stand last night (blizzard here, end of bike season :_( ) and i put it in gear running and used my pinky to shift through all the gears with perfect ease. I think it should require some level of effort to shift, but almost none needed. So easy i bet i could shift it with the blow gun from the air compressor.

 

Give a shift kit a try then. If you keep at it with your current issues, the gears will definitely get messed up.

 

Welcome to the reality of buying a cheap bike

Sh-t is generally wrong with them!


Also, when you KNOW your bike is kicking out of gear shifting without the clutch, continually doing so only helps ensure that you make the issue worse. It may have been salvageable prior to this, but it sounds like you beat your transmission into submission and then came here after it tried to kill you.


Being lazy about maintenance on a bike, as you now experienced with that huge gear slip, can potentially kill you. You might want to consider being a bit more pro-active from here on out, or purchasing a car.

 

What Jesse said. ^^^

Take your side fairings off, exhaust off, drain oil, remove oil pan, remove clutch side cover, remove clutch, remove 2 10mm bolts holding in shift drum, remove shift linkage from left side of bike, push shift linkage out of clutch side cover, remove shift fork rod, remove each shift fork, remove shift drum.

Inspect shift forks for wear (most likely 1st/2nd shift fork is worn badly, and probably 3rd/4th too)
inspect shift drum for wear (groves/scrapes)
Inspect fork rod if its bent (roll it on glass, if its bent you'll know)
Inspect shift star

You also most likely messed up the dog bones on the gears, and that requires splitting the cases... (You can see the shift dogs after removing all the above and using a flashlight from under the bike look at the cogs between the gears, if they're chewed up, cases need to be split)

Replace worn parts, get a shift kit, new gaskets and new oil.


I did the same thing with my bike (would jump out of 2nd gear into 1st when using the clutch at 5-6k rpm)
I replaced the shift fork, drum, star, spring, and oil. Did a test drive and it didnt jump out, so it may of fixed it, Or I may still have to split the cases...Bikes still being build so I wont know until I get to really ride it.

Good luck.