Hey this is my first post here but I thought someone might be able to offer me some guidance. I have had an SR125 for about a month now and went out for a long run at the weekend. I've noticed that sometimes when applying the throttle in 5th gear the engine will over-rev and the bike loses power. I think this may suggest a slipping clutch but the thing is it doesn't do it during the usual runs around town that I've been doing. It will pull away nicely in 1st, 2nd and 3rd, its only when giving it almost full throttle in the higher gears that it happens. If I reduce the throttle and re-apply it more gradually then sometimes it will accelerate as normal.

Any ides would be really helpful, cheers

Hi and welcome, The symptoms you describe are a perfect description of a slipping clutch, it will show up more in top gear than any other. make sure you have a little free play at the lever and also the actuating lever on the engine. Might be worth replacing the friction plates though if you dont know their condition!

Thanks for your response. Seems to be confirming my suspicions, it's still perfectly ride-able, especially around town so I think i will check the clutch cable and then just keep an eye on it. If I do change the plates I'd like to time it in with an oil change. Seems less of a concern today as I woke up to find someone had kindly nicked the cover off the bike so its had a thorough soaking in the rain, great!

Thanks for your response. Seems to be confirming my suspicions, it's still perfectly ride-able, especially around town so I think i will check the clutch cable and then just keep an eye on it. If I do change the plates I'd like to time it in with an oil change. Seems less of a concern today as I woke up to find someone had kindly nicked the cover off the bike so its had a thorough soaking in the rain, great!

I wouldnt waste any time checking the operating system do it as soon as, the longer that clutch is slipping is the longer it will be overheating and that will end up being dearer to fix, i have never found yam clutches to be that good at coping once they start slipping.It needs investigating and fixing PDQ.

Good thing is that Yam clutches are a Piece Of Cake to change out.

Thanks for the advice guys, this is probably really basic stuff but I've only just started out so appreciate your responses. I adjusted the clutch cable earlier on and went out on it, seems to have made a difference. Its slipping less than it was, in fact it only happened once, so I pulled over and gave the cable a little bit more slack and it didn't happen again. Will go for a longer run tomorrow so I can get up to speed and see what happens, if it all goes wrong I have breakdown cover! Oh and the haynes manual is on its way for when I do need to do some work on it.