• Hi so basically about 8 mounts ago I had a full engine rebuild after my bike seized while changing gear after this I put the engine back I. An everything was fine until a couple weeks ago when the bike kept getting stuck in neutral when changing up from 1st this happened a few times before the bike started vibrating very badly also the vibration gets worse with reva till about 5 k then the revs just shoot up to red line and it dose not feel right like the clutch is slipping

  • Engine must be balanced.

    The balancer shaft is what achieves this. It is timed up with the crankshaft. If it's not timed, you will have huge amount of vibrations through the engine.

    The clutch is also balanced and if not assembled correctly will cause vibrations.

    Others include, well there is no rubber dampening bushes that mount the engine to the frame. In other words, all vibrations are propagated through the frame so some vibrations are normal.

    If these mounts rattle loose, then there will be a noticeable increase in vibrations.

  • @Calum thanks mate Thought that it was out of balance I’ll have a look just hoping it’s nothing worse

  • @yamahadt125r244 There are timing marks on the cogs.

  • @Calum I have exactly the same problem. Any advise would be appreciated. I bought the bike not so long ago it has had a new top end (no proof) but it was fine at first then 1 day it started vibrating at high revs. Is this most likely to be the balance shaft? If so what do I look out for. I am no professional 😂

  • @Geraintuk speaking from no experience) I wouldn’t have thought so if it was fine at first then it was balanced at first it’s usually your engine mounts that may be loose

  • Check engine bolts around the frame if they come loose it will make the bike vibrate

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