Performance/Racing Variator

[AKL_HBG]

Not sure what to tell you Stig.   But the acceleration from a dead stop is slow.  Takes me forever to get to 30 MPH.  This scooter has about 150 miles on it so it is basically brand new.  I only weigh around 175 lbs so I'm a relatively light rider.

I also have a 2013 ice bear PMZ50 scooter and it will run circles around my Kymco.   That's why I am very disappointed..... Thanks

[ophelia]

Any scooter enthusiasts in your area that can take a look at your scooter? Just doesn't sound right.

I used to beat cars off the line in my Honda Metropolitan if I had my timing down. Every stop light was an opportunity. Makes me wonder if the cable throttle has a restrictor by the carburetor or something. Sometimes there's a screw that restricts maximum throttle opening.

[Stig / Major Tom]

150 miles!?
Our you still under warranty?
I'd take it back and have them ride it.
Stig

[AKL_HBG]

Yes.  It is still under warranty.  The dealer basically washed his hands with me and said that there is nothing much more he can do for me because he already derestricted it.  I had him take it back once already because it ran terrible with the new unrestricted CDI.  He then returned it to me and it runs good, but it still lacks power like I mentioned.  I also checked the CDI after he returned it and saw that it was the original Kymco OEM CDI.  I contacted him and he admitted that he reinstalled the OEM Kymco CDI because it ran better with it??  But never told me??

Now today I installed a polini variator and new sliders and tried to install a performance clutch.  The variator went smoothly but then I stripped the nut while trying to put it back on the clutch bell!!!  I'm a novice for sure, but did hand tighten the nut before using the impact wrench. 

Now I have no idea what to do.  I will contact my dealer but I'm sure he will not be much help.  I'm assuming I will have to cut the nut off somehow???  I should say not I, but a mechanic.....Happy Father's Day to me!!!

[ophelia]

Did you destroy the nut only, or did you cream the threads too?

The former is no big deal. The nut can be cracked or carefully destroyed and replaced. The threads underneath on the other hand can be gnarlier to rectify, but at least we're not dealing with the crankshaft pulley!

What did you set the impact wrench to, and did you use the right sized impact socket (assuming 17 or 19 mm)? Usually the clutch bell is usually easy to tighten. Have an assistant squeeze the rear brake lever while you torque it to the requisite 80 ft-lbs (consult service manual) or so.

edit: If the nut is securely on there, just leave it be until you need to remove the clutch bell.

[AKL_HBG]

Hi Ophelia,

I think I just destroyed the nut.  I'm not sure if I ruined the threads underneath until I get the nut off and check.

I used an electric impact wrench that I purchased just to work on the scooter.  I made sure I had the right socket and hand tightened the screw before I used the impact wrench.  I had trouble getting the kevlar belt to seat right so I tried to remove the nut and that's when it stripped.

I just ordered two special sockets to try to get this nut off.
 
I appreciate the help Ophelia.  Have a good day!  Thanks!

[ophelia]

I've slept on the issue a little. I'm surprised how rounded that nut became. The only time I've done that is when I've tried to put a nut back on a long stud, but my socket was too short to have strong contact down the entire height of the nut. The socket then shears off the top edges of the nut as it glides over without biting.

Your socket may be the right diameter, but was your socket too short? They sell impact sockets in deep and short.

Your picture is pretty fuzzy, but if the nut still has decent edges down to the bottom, zapping it with the electric impact and a deep socket may just fix your issue. Nut may just come right out. Then you can get a new replacement nut.

In the future, if you squeeze the driven pulley and push the contra spring down to make room for the belt, you can leave the clutch nut on. Usually contra springs on 50 cc aren't terribly difficult to compress by hand. Other times, I slowly spin the belt as I slide it over the variator boss on the crankshaft driving side. It's definitely easier than trying to press a tight belt onto the shaft. Tips for the next time you're in there.

[AKL_HBG]

The socket was definitely long enough to cover the entire nut.  Just not sure what happened because I test fitted the nut twice before I tried to remove it with the impact wrench.

Like a true novice I purchased a new performance clutch (which has 2K springs) thinking it would help. I did try to squeeze the driven pulley and contra spring together to get more room/extension to get the belt on, but I couldn't budge that thing! That's why I tried to remove the clutch nut again to get the belt on correctly and subsequently stripped the nut.  I had no problem squeezing the original clutch to get the belt on before.  This new performance clutch with a 2K contra spring was crazy stiff!

I've since read some forums on 2K contra springs and know think it was a bad decision....lesson learned.

Thanks again!

[hypophthalmus]

You're using metric sockets? If you're one size too large, it might tighten down fine by hand but round off the nut when you go to torque it down.

[Stig / Major Tom]

Things will get confusing if we advise someone not to use a metric socket on a metric bolt!
In future, please do not use impact wrench/gun to install a nut on a scooter. Use to remove nuts only. Hand tighten or use reliable torque wrench.
Use scooter CVT "holding tool" on the clutch ( ebay, @$12) and remove nut with your special strpped/rounded nut tool...or large channel lock pliers. Buy new nut, @$2.50.
Good luck and please keep us posted.
Stig

[hypophthalmus]

Oh, I wasn't telling them not to use metric. I was thinking that maybe if they were using standard sockets, that could possibly explain why the nut got rounded.

[AKL_HBG]

Well, I think that is where I made my mistake.  My new impact wrench did not come with metric sockets, so I used the closest one.  I used the impact wrench before on these nuts and didn't have a problem.  I guess I need to get metric sockets now.

I purchased a holding tool before so I have that and am waiting on the special removal socket and new nut to replace the one that I destroyed.

Thanks all....

[de dee]

and one other thing have 6 point sockets not 12 point,    hex  6 sides same as the nut

[ophelia]

Good call. I gave away all my 12-point sockets. I can't think of a single instance where a 12-point socket became useful, while the risk for rounding off a fastener goes up greatly. Where a 12-point socket possibly might have made sense, a ratchet head rendered that moot.

[de dee]

 you can get a socket to remove rounded nuts,  look in harbor freight, and they work well with impack guns