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General => Technical | How To => Topic started by: mrmike on July 21, 2023, 03:05:33 AM

Title: Dr Pulley sliders
Post by: mrmike on July 21, 2023, 03:05:33 AM
I'm finally ready to install my 16g Dr Pulley sliders in my X-Town 300i. While it's apart should I change the variator spring also? If so which spring would you recommend? Also looking for recommendations for a possible exhaust upgrade.
Title: Re: Dr Pulley sliders
Post by: JJJoseph on July 21, 2023, 05:30:04 AM
should I change the variator spring also?
It's likely not necessary.
Title: Re: Dr Pulley sliders
Post by: Neil955i on July 21, 2023, 06:47:05 AM
When I looked,not many options for aftermarket exhausts yet?…
Title: Re: Dr Pulley sliders
Post by: mrmike on July 21, 2023, 09:57:35 AM
It's likely not necessary.


I'll just go forward with the Dr. Pulleys and see how it runs. Will let you know.
Title: Re: Dr Pulley sliders
Post by: Ruffus on July 21, 2023, 11:56:33 AM
Stick to one change at a time. If you change several crucial parts at once, it's hard to find a failure in case afterwards.
Seem to be more work but pays off.
Title: Re: Dr Pulley sliders
Post by: NorWeWa on July 21, 2023, 02:07:32 PM
What are the gram weight of the stock rollers. ?
Title: Re: Dr Pulley sliders
Post by: Ruffus on July 21, 2023, 03:30:08 PM
Pls see link

https://www.kymcoforum.com/index.php?topic=30482.0
Title: Re: Dr Pulley sliders
Post by: mrmike on July 21, 2023, 08:36:32 PM
Thank you for that link. If it's correct, I have 17.5g rollers in my variator. Dropping to 16g sliders should give me the added performance I want. I'll be installing them next week and will report back.
Title: Re: Dr Pulley sliders
Post by: mrmike on July 23, 2023, 12:46:00 PM
Now I'm really upset. I got the scooter apart only to discover that the Dr. Pulley sliders I have and the stock rollers are all the same 15g. Is their any advantage to just swapping the same weight rollers for sliders? What would be the quickest source to get lighter 13 or 14g sliders.
Title: Re: Dr Pulley sliders
Post by: Stig / Major Tom on July 23, 2023, 04:23:44 PM
Now I'm really upset. I got the scooter apart only to discover that the Dr. Pulley sliders I have and the stock rollers are all the same 15g. Is their any advantage to just swapping the same weight rollers for sliders? What would be the quickest source to get lighter 13 or 14g sliders.
Yes. There is a difference between roller and slider behavior.
It's been too many years to recall what it was🙃
Sliders act like heavier rollers....I think. Or vice-versa.
Stig
Title: Re: Dr Pulley sliders
Post by: Ruffus on July 23, 2023, 05:30:45 PM
To lighten rollers/sliders is very easy.

You need a gram scale, a drill and some patience.
Sliders and rollers have brass inerts.

Put desired pieces into a vice, preferable under a bench drill and carve out as much as you need to.

Pls see link...
https://www.kymcoforum.com/index.php?topic=30655.0
Title: Re: Dr Pulley sliders
Post by: NorWeWa on July 23, 2023, 05:50:07 PM
Stock for your X-Town 300, is 17.5 grams.  You found 15 gram rollers installed. The 15 gram Dr Pulley sliders will not act exactly the same as the 15 gram rollers.  Install the sliders and give it a try. 
Title: Re: Dr Pulley sliders
Post by: mrmike on July 24, 2023, 02:07:18 PM
I weighed the Dr. Pulley sliders I bought at 15G. When I took my variator apart, the stock rollers were also 15g. I installed the sliders yesterday. The scooter seems to run ok, but my tach is reading extremely high. The motor doesn't sound like it is revving as high as the tach is reading. Could I have done something to the tach with the slider changeover?
Title: Re: Dr Pulley sliders
Post by: NorWeWa on July 24, 2023, 02:21:58 PM
Not sure what you expected.  Increased RPM is the result of the lighter weight sliders and rollers over stock rollers.
Title: Re: Dr Pulley sliders
Post by: Stig / Major Tom on July 24, 2023, 03:11:53 PM
I weighed the Dr. Pulley sliders I bought at 15G. When I took my variator apart, the stock rollers were also 15g. I installed the sliders yesterday. The scooter seems to run ok, but my tach is reading extremely high. The motor doesn't sound like it is revving as high as the tach is reading. Could I have done something to the tach with the slider changeover?
No. I think your motor is revving just as your tach is displaying.
Your revs have increased across the board of your ground speed. In other words - at 35mph your engine is now revving higher than it did with stock rollers - because of this increase in rpm's your throttle response is greater - "more power" when you twist.

Me - I didn't like that my engine was revving higher than previously at 30mph. I didn't care that the increased revs gave me "more snap", "more power" when I twisted the throttle...to me it was like driving around while failing to shift up to the next gear.

Some like that "extra power" on tap....and do not mind the increased revs.

The major Vespa dealer in SoCal recommends going nearly 3gm lighter in roller weights in my Liberty - "to release that hidden power" in my motor. No thanks. Piaggio has my little 155cc aircooled motor revving just as it should be for long life. They've made over 900,000 of these scooters....

Stig
Title: Re: Dr Pulley sliders
Post by: NorWeWa on July 24, 2023, 03:33:22 PM
If you feel the increased RPM is not what you wanted, best to go back to the stock 17 gram rollers. 
Title: Re: Dr Pulley sliders
Post by: Ruffus on July 24, 2023, 05:31:58 PM
Buy several sets of different weights and experiment with.
Title: Re: Dr Pulley sliders
Post by: mrmike on July 24, 2023, 10:23:14 PM
 The new sliders are not lighter. I weighed all the new sliders and all the factory rollers. The scale read 15g for all of them. Just changing from rollers to sliders that weigh the same. I don't get it.
Title: Re: Dr Pulley sliders
Post by: Stig / Major Tom on July 24, 2023, 11:44:33 PM
Watch some youtubes on DrP's....see what makes them different.
Stig
See info
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Buggy Parts NW
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