Piaggio AC 2T problem! :(

Discussion in 'Maxiscooter Tuning' started by bertie, Jun 22, 2010.

  1. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    Right fella's, got problems with my old skipper 125 again!

    Problem is: 0 - 30mph is a total flat spot, cannot get any revs out of it untill atleast 35mph. Then she shoots upto 60 sharpish.

    I thought heavy or worn rollers, the rollers inside were: Malossi 12.5g and 7.7g mixed, some had squared out a little. So I brought a set of genuine piaggio 12.5g rollers, fitted them and the problem is WORSE! Same problem, just a longer flat spot than before.

    So, I take the rear pully and clutch off, the pullys were stiff so I greased up the torque drive and shes moving nice now... Fresh belt.. And STILL got rubbish pull off and its dead slow to 30mph, then as before takes off like a rocket at 35mph.

    So im thinking about getting some really light rollers, 8g/9g/10g. but I still feel this wont solve the problem as its a standard bike and the standard weights are 12.5g! (what im running now!)

    Any clues please guys?
     
  2. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    welll well well....erm, id say check your choke, the inlet for any splits, the air box for any splits/cracks or holes and check all your vac lines. you have headed straight to the most probable cause of the problem wich is good... has the bike done this since you have owned it or has it suddenly developed?
     
  3. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    Since I owned it minor, although my manifold is starting to crack like old tyres, I cant see it being the problem as the engine runs really nice, ticks over perfect and screams when it eventually gets going. And revs nice and cleanly on the stand, it doesnt actually bog down it feels like something holding it back like a really tight drive belt

    The choke seems to work, I havent actually checked but from a cold start it cuts in (higher tickover) and cuts out (lower tickover) as normal.

    Im still kinda thinking it could be the belt because its got a aftermarket one right now (not a race belt, more like a europarts spares thing).. And it seems alot thinner than a piaggio belt.

    I tried my spare thicker & shorter piaggio belt and this made the problem even worse.

    Are 125 2T belts thinner than normal belts? I have a zip 50 belt and what I suspect to be a Vespa GT200 belt, and this aftermarket belt in the skipper is thinner and longer than both?
     
  4. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    it will be longer but should also be alot thicker than the zip 50 belt.... take a picture of your front pulley/clutch bell/clutch (front and back) and every part you find between the variator nut and the oil pump drive gear.

    will most probably be the problem. somone at some point has bodged this up :) first things first. order the correct belt for THIS moddel of bike of the correct year (assuming the engine is the original one) and go from there. are you SURE the stock weight is 12.5g? its more down to gearing/vehicle weight so it could be that 12.5g isnt the stock weight. i dont know off the top of my head....

    but ye, lots to try still... could have just half fucked a seal and it needs a few mins running to fill back up with oil and "seal" the case once again. can be all manner of things. but if its consistantly performing the way it is then yes it is most probably transmission related
     
  5. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    UPDATE UPDATE UPDATE!!

    Right, I picked up a new drive belt today spending my minimoto project funds to get this old git running nice..

    Its deffo the correct belt this time, I made sure the shop checked the part number against my frame and engine number so I get the correct belt.

    Swapped belts over, this new one is thicker and tighter just like the other piaggio belt I have already tried.

    But now im getting 70mph clock speed! Finally... but theres still a HUGE flat spot from 0-50mph... I have to kick off like a push scooter to get the ped moving! Then it'll crawl to 50mph slower than a 50cc ped, then eventually get to 70mph..

    Its unsafe to ride now, its that slow. If theres a car coming from 2miles away, i cant pull out on him, its that slow from 0-30. and 30-50 is just as bad. 50-70 is ok but still not pulling like a 125 should!

    Really need some help now, Im getting to the point now that I want to sell the bike.

    I miss my zip70!!!

    EDIT: I made this post at the same time as you just posted (minor), and im gonna strip the tranny down again for you tomorrow and get some pics of all the parts, I actually know the order they are in right now off the top of my head, il write it out now but still post pics tomorrow.

    Variator side: 18mm nut >> kickstart cog >> Washer >> pully >> washer >> belt >> variator (with brass plate & 3 screws), behind that is another brass casing I assume is hiding/protecting the oil pump belt.

    Clutch side: 18mm nut >> clutch bell >> Whole thing comes off in one unit, leaving the greased up "pin" and a bearing on the shaft.
     
  6. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    think you have a spacer missing thus your gearing is probably retarded heavily... ill try get a pic of my stock typh engine order (check if theres a spacer.. long day, brain's fry'd) i use the bike for work tho so probably wont be till friday afternoon at the earliest. but ye, check your clutch/swap it if possible... it may well be worn to fuck (springs in clutches do loose there stiffness just like anything steel thats exposed to the elements for 10+ years) this would deffinatly cause the above symptoms
     
  7. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    Ahh cheers Minor I think you've just pointed out something I missed, the spacer, and on my bike theres No spacer between the front pullys, just a thin washer that sits in a slot behind the front "fan" pully. But no seperate washer between the pully and variator. There is a slide pin though just like the clutch side has.

    I just bombed down the A3 and after 2 or 3 miles of full throttle I got 72-73mph on the clocks, 60-70mph is quick, the rest is just dead, worse than a 50 4T!

    But yea thanks for helping me with this I will have pics up of my entire transmission tomorrow afternoon around 5-6pm!
     
  8. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    Ok Minor I got some pics for you today, only from the variator side because I didnt take the clutch and rear pullys off, because I had no one with me to help slack up the belt when putting it back together.

    Heres a pic of it complete:
    [​IMG]

    Uploaded with ImageShack.us

    Tranny case off:
    [​IMG]

    Uploaded with ImageShack.us

    Heres a pic of the belt, probably too blurey to see the code but im sure its the right one:
    [​IMG]

    Uploaded with ImageShack.us

    In order from left to right: 18mm nut, kickstart cog, washer
    [​IMG]

    Uploaded with ImageShack.us

    Picture after removing the items above:
    [​IMG]

    Uploaded with ImageShack.us

    Front fan pully off, with washer that sits in the slot next to it:
    [​IMG]

    Uploaded with ImageShack.us


    Heres the pic youve been waiting for, what looks like a spacer in there is actually the big pin that goes inside the variator when re-assembling:
    [​IMG]

    Uploaded with ImageShack.us

    Heres all the parts in order from left to right (is that big pin supposed to be greased?)
    [​IMG]

    Uploaded with ImageShack.us


    The bare crank, only a spacer at the back there for the oil pump drive belt (unless thats the spacer im missing??)
    [​IMG]

    Uploaded with ImageShack.us
     
  9. bertie

    bertie Active Member

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    1,440
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    '93 Skipper LX125
    Heres one of the variator in bits:
    [​IMG]

    Uploaded with ImageShack.us

    Its got the rubber o ring for the brass plate too.. Also, it was filthy and had 17yrs of roller gunk build up.. After a good clean and putting the malossi rollers back in (3 x 12.5g and 3 x 7.7g), made a fair difference in acceleration, its still pig slow and will not rev, the revs build up with speed, at 70mph the engine is screaming, if Im cruising at 50mph, then whack the throttle back theres NO difference in revs, just sound. Then it'll crawl upto 70mph.
     
  10. Blue dwarf

    Blue dwarf New Member

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    342
    What size rollers are you running? I mean physical size? 20 x 17 or 19 x 17?
     
  11. bertie

    bertie Active Member

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    '93 Skipper LX125
    im not sure as i brought them from a shop so I assume they are 19 x 17... 3 x 12.5g and 3 x 7.7g

    Im sure im missing a spacer or something in the transmission.. just waiting for minor to check my pics above
     
  12. Blue dwarf

    Blue dwarf New Member

    Messages:
    342
    I`d suggest you measure them,
    I may be wrong but you could be useing 20 x 17 rollers in what is definately a 125 variator and it does make a difference.
    Just do a quick check and it`ll rule that out.

    Looking at your pic of the transmission complete and belt fitted I`d say your belt is sitting too low down in the torque driver, it should be riding almost at the top of the rear pulleys, meaning your variator is pushed together too much to start.
    This could be spacing or too short a belt.
     
  13. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    first pic of the tranny cover off. does the belt always ride this low on the clutch pulleys?? it should be ALL the way to the rim of the clutch when you first take the case off.... start it up, go for a ride an whip the cover back off... if the belts sitting this low then thats your problem. ether your front pulley is too far "in" on the crank or the belt is infact too short. the roller diameter could cause spacing issues, but thats somthing seriously amis. ill rip mine apart in a min for ya :)
     
  14. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    Minor your a legand! some pics of your transmission would certainly help. Did you spot any missing spacers in the pic of all parts layed out?

    And yes the belt does sit that low in the clutch pullys at tickover, its never sat right at the lip since ive had it, the skinny belt that was in there before sat even lower.

    So that sounds like the problem.. I just need someone to confirm theres a spacer missing from the pics above. There is a washer between the fan pully and vari, but it sits in a slot on the fan pully (check pics), this doesent seem like a spacer to me its a wafer thin washer?

    Roller wise: The blue ones in the picture were sold to me by CBS whitton, he assured me they were standard 12.2g 125 typhoon rollers. So id imagine thats 19x17mm but they do look smaller in size to the Malossi rollers im running now.
    The bike runs better with the malossi rollers (mixed weight 12.5 and 7.7), and they also sit better in the variator, the blue ones have room to rattle around in the sockets (and you can hear them at tickover) With the malossi's its smooth and quiet.

    I will however order some off the internet, as my local shops are always giving me wrong parts.
     
  15. bertie

    bertie Active Member

    Messages:
    1,440
    Rides:
    '93 Skipper LX125
    I've just been looking at the blueprint of the trasmission for the 125 ac engine, and it looks the same as mine, so i dont think im missing a spacer or anything?

    But now im thinking its the belt being too short again.. Minor, if you do take pics of your transmisson for me can you tell me the codes on your drive belt? So I can see if mine is a match. cheeeers
     
  16. Blue dwarf

    Blue dwarf New Member

    Messages:
    342
    125 belt is 832mm by 18.5 wide.

    180 belt is 836mm by 18.5 wide.

    Save you buying the wrong belt again why not just buy a Polini 180 belt part number 248.018 that way at least you know the belt is right and long enough.
     
  17. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    Thanks blue dwarf, and would the 180 belt work fine in a 125 tranny?
     
  18. nrgandy

    nrgandy New Member

    Messages:
    2,180
    deffo looks like a short belt tbh or something to do with rear pulleys ive got skipper pulleys if you need any thats if yours is a series one engine. try another belt from a typh/runner etc and see how it goes
     
  19. bertie

    bertie Active Member

    Messages:
    1,440
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    '93 Skipper LX125
    Would the pullys in my skipper be different compared to pullys from a typhoon or anyother aircooled 125 engine?

    I was under the impression that my skipper has a typhoon engine? And im sure the gearing is the same as a typhoon because ive had 75mph down hill out of it, and its getting to 70mph on flat roads, just takes the piss getting there. Seriously, im getting done by 50 4 strokes off the lights.
     
  20. nrgandy

    nrgandy New Member

    Messages:
    2,180
    should have the same transmition as typhs etc and no there normally good on set off (burnouts/wheelies from the throttle) on a near stock 125 just with a few small parts
     

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