2001 yz problem.... Help!

Hey! I'm new to all this forum stuff and motocross! I bought a 2001 yz 125 a couple days ago! Just had new barrel and top end rebuild! I toke it out to the local track yesterday! Started off all fine! I started gettin more confidant and opened it up! I went from second to 3thrid and it didn't sound like I changed gear but I had. Then went 3rd to 4th and still the same and powerband was just screaming but didn't seen to shift much considering I was giving it the full beans. Below powerband it pulls ok I guess( I'm 15 and half stone) so I'm not exspecting the 125 to be 2 pokey below powerband! Any1 got any suggestions what it could be ? I'd be really glad for the help. Thanks Ben :)

are you sure your shifting? Ive seen people have bent shifters and not realize it, but the shifter would hit the ignition cover and not allow them to bump it up all the way. Just a thought.


I guess I said my first question wrong.. are you sure your bumping the shifter all the way up?

Hey bud! Yea I slowed right down a couple of times and made sure and then I went round again full throttle and really pushed the shifter up and it's still the same. I thought maybe the clutch could be slipping.. But y only in powerband?? Lol I really don't know

Well if your clutches are wore out, once you really start making power it could cause slipping. If I saw how your bike was running in person I could give a better answer. I have had a few YZ125's and worked on plenty of them. A very common problem with them is the power valve linkage that goes up to the powervalve from the right side case will break, that could be something to look into (if it is feeling weak up top). I had a 98' YZ125 before that the shift shaft actually separated from the shifting lever that actually turns the shift drum so that I could not shift at all. It popped out from the bike falling on its left side and the shift shaft being pushed hard towards the right side of the bike. Does it shift fine from say neutral  to first? and first to second? Have you done a compression test? Could be overdue for a topend and just having a weak motor due to this.

It's had a brand new barrell and top end rebuild about 2 hours ago(so the guy said) can tell the barrell is new though .

And yea it goes into gear ok

It's had a brand new barrell and top end rebuild about 2 hours ago(so the guy said) can tell the barrell is new though .

And yea it goes into gear ok

w t f is a barrel

Well I know it as a barrel like I said in NEW to all this ImageUploadedByThumper Talk1380218730.911723.jpg. The bit above the yamaha writing!

I think you are talking about the cylinder/jug

Edited by FishSticks

That's most proberly what it is :)

That's most proberly what it is :)

the bike looks really clean in that pic

It is a clean bike for its age.. Could do with some new handle bars and grips and plastics and graphics! But because iv just started Riding I don't want to put new graphics on incase I keep coming off. Just need to get the problem sorted.

It is a clean bike for its age.. Could do with some new handle bars and grips and plastics and graphics! But because iv just started Riding I don't want to put new graphics on incase I keep coming off. Just need to get the problem sorted.

what country are you in?

England

Thought I would let you guys know it was the clutch plates on there way out! Just incase any1 else is havin the same problem

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