Hi I’ve posted on here recently about my honda cbr 125r jumping gears like from second down to neutral it’s self yesterday and today it’s got a lot worse now as I’m riding going through 1st, 2nd,3rd and 4th it’s jumping all ways up and down sometimes over reviving then the bike sounds so tinny like less power and everything like so high I was told gear selector forks but I want to “is this a big job ???” And I don’t know if this is a silly question some may laugh but I need to ask like yesterday by bike hadn’t been out on the road and was left standing for the whole day in like 22 degrees heat could this affect it in anyway ? As it’s only started jumping gears after this I’ve also been told about clutch adjustments but I’ve really no idea where to start I know where the adjuster is but where to set it at I have no clue if anyone can answer my question it will be much appreciated thank you.

 

Am assuming your FI have a look in here
https://www.manualslib.com/manual/12...?page=3#manual

 

Hello thank you for that should definitely be a help, funny thing is that what I mentioned about the gear jumping I kept my bike out the sun all day yesterday getting on this morning and not one gear has jumped the power feels like it’s there again it’s so weird mind if it’s own,,, I have just put a new chain on last week as other was stretched and pretty battered I also did an oil change and changed spark plug after the oil change should I have changed the oil filter to ?

 

Always worth doing the filter at the same time as most Oil change kits come with filter , but if I remember your bike is low Mileage ,but certainly do it next time, Is your bike Fuel Injected as that is the right manual for it, Page 3-24 will show the adjustment if needed

 

It is fuel injected yes the gear jumping and loss of power was crazy, just don’t understand it sometimes one day it’s amazing so smooth the next it’s like jumping over revving and stuff I might drop the new oil today refill and do the filter to I’ll also look in to that manual thank you

 

Is this the correct oil ?

 

Think I would use this,Silkolene Comp 4 10w-40

 

That is what was put in last week but my friend didn’t add the whole litre, and I can’t understand why because I’m pretty sure it’s supposed to take a full litre correct ?

 

Yes forgot you only have a strainer on these instead of a oil filter , but they might not take the whole 1 Ltr as there would still be residual oil in the block, just check your strainer is clean, and once in check the oil level until as much as needed is in

 

Ok thanks a lot all the info given much appreciate it