Very hard shifting and clunking into gear

Try changing oil in crankcase, bad oil can cause hard shifting

Could be your clutch not properly disengaging due to bad plates, grime in the clutch basket from prolonged oil changes, or something else you would have to have a pro look at it and figure out. Id start by changing the oil and going from there.

I had a CBR that I had the same issue with. Sometimes it would go into gear, sometimes not. I would recommend lubricating the shifting assembly really good and checking it for proper adjustment. Sometimes adjusting the shift level will sovle this problem. Also changing the transmission oil can help in certain circumstances. If you are not using synthetic oil in your clutch case you can try a semi-synthetic oil and seee if that helps. If it does and you do not experience any clutch slippage then you can gradullay go to full synthetic. If you experience slipping change back to regular conventional. If you are using synthetic now they make additives that you can put in the transmission case to help the tranny shift more smoothly.

the only thing would be over filling the oil, or not waiting long enough for the new oil to settle down . wait an hour after oil change to start bike.

If the shift pedal is hard to push down and/or hard to lift up, the problem is a bent shift fork. If it feels like it always did, then I have to ask if you have changed oil in the last month or so. Did you use anything other than standard 10w40 motor oil? Synthetics and oils with "special" additives can make a clutch fail to engage. Some of them swell the friction plates and the clutch will not dis-engage. If you did use the wrong oil, drain it and flush it from the gearbox as best you can. The clutch may or may not return to normal.

Can I get a “very helpful” rating on this answer?

whats happening is your clutch plates are sticking together. try tightening up the clutch cable a bit. im not sure if it is cable, it may be hydraulic? if it is, then bleed the clutch to get any air out of the system. if that doesnt work, then try an oil change. sometimes old, thick oil wont let the clutch plates seperate, and you get that jerking when your engine is cold. use a light oil. maybe 5-30 or 10-30. a light oil will make it easier for the clutch to disengage.

One of two things is happening. One is the cost of a double oil change and filter. The other requires your banks loan officer.

Change gearbox oil and install a new oil filter. Dirt and grit in the oil is binding the gears and shift drum. Ride the bike for a couple of hours. Now drain the oil again and put in fresh oil. This will flush out the dirt and grit. Use 10w40 motor oil. Stick with the major brands; Pennzoil, Quaker State, Mobil or Shell. If dirty oil is not the problem at least we eliminated the possibility for only the cost of a few quarts of oil.

Now let's talk about that loan officer. The shop is going to charge around $1000 plus to replace a bent shift fork. This is not a repair for the untrained. Sorry.

check the compression it may need a ring job

when the last time you made a tranny oil change ? or also check the level of oil when all that is done youncan get more technical lets see could be the shift bushing ... easy to install and if its a tranny probleme well maybe time to get that corvette you always wanted go big or go home ahahah good luck

Just a piece of advice: could be the oil which lubricates the gears. Try changing your engine oil, maybe it has gotten a little too old and lost its lubricating properties.