The bike keeps shifting gears on its own what is wrong

when shifting gears on bikes you have to keep pedalling but with out load on the chain
shift one gear at a time as multiple gear selections may cause chain jump
do not pedal backwards as the selector is for forward motion only

It means its an 18 speed bike. The shifting is easy. Start with the left side, begin riding, keep pedaling, don't stop pedaling in ther middle of a shift, it will throw the chain. As you ride, twist the shift grip, up and back. Still pedaling? Now after you have tried that one, try the other side, its the rear with 6 gears. Up and back, keep pedaling. After you have tried each individually, try them together. And now you're shifting. Looking good
. KEEP Pedaling

dont go that much fast for first1000kms...affects engine life...

New forks will certainly help.

Rock the bike back and forth, to loosen the clutch plates taking the load off the gears so you can shift up.

hi, if when you start your bike you press the gear lever down to go to 1st from neutral and then pull it back up to go to 2nd,3rd,4th and 5th then the only way to get back into first gear is to press the gear lever down 4 times to get it back into 1st gear their is no quicker way to do this you have to work your way back down the gears.

if your coming to a stop quick then just pull the clutch in and keep pushing the lever down until it dont push down any further it will only go down 1 gear at a time so you will need to push it down 4 times but you dont need to count you can just keep pressing it down the gears until it dont go down any more then you know this is first, you need to keep the clutch in when doing this.

how ever if your slowing down is more gradual then what you can do is go from 5th down to 4th then let engine slow the bike down then when the revs drop down change down to 3rd and so on until you get ot 1st gear.

if your coming to a stop quick say at lights or junction then if the bike is in 5th gear then you can change down the gears once the bike has stopped just hold the clutch in when you stop and keep tapping the gear lever down until you feel that its not going down any more gears this way you know its in 1st without having to cound down the gears, their id no quicker way of going down the gears to get to 1st.

i hope i have read your question right and gave you the answer you was looking for if i got the question wrong then please explain then i can assist you further ok

hi,i dont know a lot about this particular bike,but,as with any high revving sports bike you will need to keep the revs up before changing gear,an 883 sportster has a lot more torque than your bike and you can "short shift "them and let the torque do the work,however on a cbr i think you will need more rpm before you shift as they dont have the torque of your old harley,a friend of mine has an r6 yamaha,that thing revs out to nearly 17000 rpm he doesnt change untill about 9 or 10000 rpm,from memory your bike should be capable of nearly 60mph in first gear..hope this helps...cheers

Im not sure how you ride your bike but if you "beat on it shifting without cluch sometimes the fork in the transmission gets bent...this is the only reason that would cause hard shifting besides wrong gear lube

Wish I could come up with a line of B.S. as good as their service department does. You have a slightly bent shift fork. Tell the jerks to fix it. It is a problem, it is not right, and it is covered under warranty. Tell them you really don't want to get creamed when the bike pops out of gear and doesn't want to go back into gear as a cement truck is coming at you. If you let them stall you until the warranty runs out it will cost you around $1400.00 to get it fixed. Contact the Regional manager for Yamaha ASAP. Google "Yamaha Motor Corporation" http://www.yamaha-motor.com/
What I am afraid will happen is that the dealer will do the repair and install a new shift fork then tell you they could not find anything wrong so you now owe them the cash because Yamaha will not stand the repair cost for a non-existent problem. Send Yamaha a certified letter as to your concerns and insist someone other than the dealer inspect the bike to confirm the problem. Keep a copy of the letter and the postal receipt. Is there another dealer in the area?

The diagram below shows how a shift fork moves a slider gear left and right to change gears. A slightly bent shift fork would not let the slider gear "dogs" fully engage into 1st gear.

A “very helpful” rating for this answer? Thanks!

Check the gears mabey they are skipping when the bike goes to fast. like at 3/4 throttle theres to much torque an it just wont catch.