Kymco Super 8 rattling sound

Discussion in 'General Scooter Discussion' started by Brie, Apr 17, 2017.

  1. Brie

    Brie New Member

    Messages:
    21
    Last week I noticed a rattling sound especially during idling. I have checked all screws and nothing is loose. Scooter is running perfect but I want to know what causes this sound, any ideas?

    It just passed 500 miles but is as mentioned above running perfect.

    Thanks!

    youtu.be/VHn84OxZsr0
     
  2. MrXT

    MrXT Active Member

    Messages:
    534
    At such a low milage I assume you must have bought it new so it must be under warranty so I would suggest bringing it back and asking them. It sounds like a loose bolt on the exhaust, you sure you checked them all? With a torque wrench and not just your fingers?
     
  3. Brie

    Brie New Member

    Messages:
    21
    Thanks!

    Sorry I meant 5000 miles (7000km). Took apart the fan area today and noticed that I got a cracking noise when turning it over. However, after removing the variator the fan turned butter smooth again which makes me believe that the problem must be in the variator. No play in the crankshaft either so I don`t think it is the bearings.

    Installed DR Pulley weights a couple a weeks ago and this is how they look like today. Can`t be right, or?

    [​IMG][​IMG]
    [​IMG]
    [​IMG]
     
  4. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    change to rollers , those DR slider have been shot to bits, highly worn out and sticking , 3oclock and 9oclock shows marked wear on the ramp bottoms , i would say this is the problem.....

    change out to rollers of the same weight and size see if that helps change things up ;) also gonna be a darn sight cheaper than the DR sliders they cost an arm and a leg ( are your sure they are original DR sliders ? , fake ones are known to be around and made from inferior materials )
     
  5. gilburton

    gilburton Active Member

    Messages:
    558
    Get yourself another variator with rollers as the damage will cause further problems. Kymco stuff is reasonably cheap in the UK but not sure about Sweden?
     
  6. Brie

    Brie New Member

    Messages:
    21
    Thanks!

    Tried rollers today but no difference, I have still have this rattling sound on the fan side.

    Tore apart the fan side of the motor and found nothing that looked wrong. However, this is the sound I get when I turn the gears that are inside.

    What could cause this sound? Could it be something with the starter clutch? I have noticed that the starter slips occasionally whichs means that I have to release the start button and press it again to get the starter to grip and turn the motor around.

    Note, I have no play in the crankshaft either on the fan side or on the variator side so I doubt it could be the bearings. Only play I have is maybe .5mm back and forth but no play left and right.

     
  7. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    ok thats not coming from the variator , that sounds more like ring binding ie piston rings chaffing the cylinder.

    notice when your start to get the piston to top dead center your hearing that grating sound . you may need to decamp the head and cylinder and check the piston and rings and cylinder sleeve for any damage .
     
  8. Brie

    Brie New Member

    Messages:
    21
    Looked at the flywheel today and noticed 4 indents approx 90 degrees apart inside of it. Also noticed some scraping marks on the magnet. When I rotated it by hand I couldn`t see that it was hitting the pickup coil.

    Should it look like this?


    [​IMG]

    [​IMG]

    [​IMG]
     
  9. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    the bottom picture is the pickup nugget. this part swings past the pickup sensor and sends a pulse to the cdi. it should NOT hit the sensor . if the sensor hits the nugget it can become damaged and then fail to send a pulse to the cdi triggering the spark.

    That nugget on the fly wheel has to pass the pickup coil , rotate it so it sits below the pickup sensor and slip a credit card between it and the sensor there should be a gap . you may find that the pickup coil mounting spots are pre set and give the pickup sensor a preset distance from the flywheel nugget, thats all good to.

    the indents inside the flywheel show the magnets that produce the voltage and current that are induced into the stator coils. four magnets or more are imbedded into the flywheel as it rotates it induces a current and voltage in the stator coils and thats what give us the bikes electrical power. they are perfectly fine some flywheels are smooth some have little indents like yours.
     
  10. Brie

    Brie New Member

    Messages:
    21
    Ok, thanks for the reply. Then I guess the flywheel has nothing to do with my grinding noise.

    Someone on another forum told me that he has had a similar grinding noise and that he just removed the variator and then assembled the flywheel and fan first and last assembled the variator. He wrote something about that this shifted the crankshaft slightly which stopped his scooter from sounding so nasty.

    Sounds like a very strange solution to me, what do you think?
     
  11. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    its hard to say Brie strange solution but its possible that putting the flywheel on first is settling the bearings and crank, where tighening up the variator first could be pulling the crank and causing flywheel to chaffe or run on the bearing faces.

    see if the solution you mentioned works and come back if its still a bit noisey.
     
  12. Brie

    Brie New Member

    Messages:
    21
    Thanks for you prompt replies. Really appreciated.

    I have ordered a new gasket for my right engine cover and will wait for this to arrive before re-assembling everything.

    I will be back :)
     
  13. Brie

    Brie New Member

    Messages:
    21
    New update.

    Opened the variator today and found that the boss has a very loose fit into the variator. Should it be this loose? Could this be the rattling sound I hear when engine is running (variator vibrating on the varitorboss)?

    Also, the grinding noise must be the belt. When removing the belt there is no noise when I turn the flywheel but when I install the belt there is a loud noise. Se below videos.

    What do you think, will all my problems go away if I just replace the front variator?

    Many thanks!



     
  14. gilburton

    gilburton Active Member

    Messages:
    558
    Variator is well worn. It should be a tight but sliding fit.
    It certainly shouldn't "wobble".
    A new one is required. (or a good secondhand one)
     
  15. Brie

    Brie New Member

    Messages:
    21
    But do you think this is causing the rattling sound in the motor? After tightening the variator nut the variator is still a snug fit. See video.

     
  16. gilburton

    gilburton Active Member

    Messages:
    558
    It won't be running true. Irrespective of the noise it's worn so needs replacing.
    It's a good bet it is causing the noise.
    Instead of wobbling the bush/boss imagine it solid and the sliding pulley wobbling on it as it moves out/in.
    The bush/boss may also be worn.
    Take the belt off bolt the variator back up and then try moving the rear half.
    This may be why your sliders were worn after a short time.
     
    Last edited: Apr 20, 2017
  17. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    Yes brie , that variator boss has worn the inner liner of the variator itself and thats whats giving the rattle i would say.

    the variator should slide up and down the variator boss it should not float left-right in a wiggle it should be nice and tight but allowed to slide.
    a new variator and boss will show how they are meant to be....... i would say that poor variator has never been checked or seen daylight until you found the problem at hand and your fairly lucky to catch it now, any longer and damage could have started to happen on the crank shaft and bearings due to that wobbling variator.
     
  18. Brie

    Brie New Member

    Messages:
    21
    Thanks!

    Do you also think that it is the belt that is causing what I call grinding noice?
     
  19. gilburton

    gilburton Active Member

    Messages:
    558
    It's probably because the pulley is not turning concentricaly so as you turn it it's gripping then letting go.
    In my opinion get a belt as well as the worn boss has also worn the belt.
     
  20. Tamiyacowboy

    Tamiyacowboy Pippa's Owner

    Messages:
    1,850
    Rides:
    Piaggio Skipper
    i agree with Gil . a new belt will not hurt you cannot tell how bad damaged the belt could be, surface wise it may look fine and measurement wise be in spec to service manual specs but that grip and slip from the wobble could have cause it to stretch on one side and not the other.

    A new belt and variator with boss is going to be the best fix , no wobble and a lovely fresh new belt should be just right. if your looking to upgrade go for something like a malossi multivar 2000 variator as an upgrade its going to show when installed with better ramps so your going to notice a difference from the stock old one right from the word go , pull away will be better and ratio transition to, good thing is you also get a new contrast spring for your rear clutch pulley to , thats going to help with transition from low to high and high to low ratios ;)
     

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