2stroke clutch pulley - does size matter?

Discussion in 'Scooter Tuning' started by Buzz, Aug 16, 2017.

  1. Buzz

    Buzz Active Member

    Messages:
    446
    Hi I have just received a new clutch torque drive for gilera dna 50. I now realise that the old clutch pulleys are considerably bigger. The new pulleys are about 117mm and match the clutch bell and variator whereas the old one had 135mm pulleys?! (Stuck out wider than the bell)
    Which is the right size for the scooter? Is the old large one for a 125cc maybe or have I been sent the wrong new torque drive?
    It seems the belt will ride right up on the pulley edge which worries me (825mm belt)
    Is a larger pulley better or will it make no difference?
    Thanks
     
  2. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    hard one to say Buzz.

    we tend to overdirve the rear pulley on some models of scoot meaning we add a larger rear pulley so we can slip a slighlty longer belt on and get a slightly higher ratio on gearing.

    could you not get a rebuild kit for the older pulley, ie set of new pulley oil seals and seats that should give you a new lease of life or are the guide pins worn and the guide groves ?
     
  3. Buzz

    Buzz Active Member

    Messages:
    446
    Interesting answer, I spent the best part of the day swapping out rollers, contraspring and clutch torque pulleys to find the optimum set up for this bike... best set up was with the original larger pulley and a slightly longer belt! Exactly what you just said so a thumbs up to you. The old clutch pulley was becoming very loose and seemed to stick occasionally but runs far better than the smaller new one. I stripped out the pins and swapped them over, regreased and used a plastic slip ring on the contraspring and all feels good.
    Once I work out why the speedo isn't reading then all will be great for my youngest lad to take up the reins and follow me and his brother into the two wheeled world.
     
  4. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    have a look at the dashboard connector for speedo, they can sometimes work loose and unscrew themself from the rear of dash just enough for cable to slip out of the catchment and you loose the worm drive feed to the needle.

    if thats all good , its then the wheel side of the speedo unit possible its worn out and may need replacing , or its a cable problem like above, its gotten loose and somewhat slipped outta the worm drive catchment. the cables tend to have sqaure ends that slot into a squared receptical that allows the worm gearing to drive the needle and give the speedo life .

    i was gonna say do a cowboy and swap out the pins from new into oldie and give it a whirl , but sounds like you already hit that puppy up and got its all pucker.
     
  5. Buzz

    Buzz Active Member

    Messages:
    446
    Hi thanks for the replies, it's appreciated; I might swap the rubber seals over as well now you mention it. I'll check the speedo where you say and see what I find.
     

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