Higher RPM Clutch Engage

[TBR125]

Hi,

I have found the clutch engage rpm of my Agility 125 has been lowering over the years. New engage rpm was 3,600, now it is down to 2,455. I would like to raise it to 4000-4500. How do I know what stiffness spring to buy? What is the pound compression of the stock? Any input is appreciated.

I am also dropping to 12 gram Dr. pulley sliders as more power is needed for the larger variator pulley I installed.

[Iahawk]

I've never paid a lot of attention to the various clutch pad springs available...but it seems like they are always color coded to their level of stiffness (soft, medium, firm)..how stiff are they, exactly? who knows!

It would probably be helpful to reach out to one of the online scooter parts sellers and see if you can talk to a knowledgeable person.

Your Agility 125cc motor probably falls very nicely in line with the more common Chinese GY6 150 cc motors so there should be plenty of options out there for you.

I follow a few scooter shops on youtube that also have a strong online parts presence... scooter swap shop in Portland and rolling wrench in Denver are 2 that come to mind.

[TBR125]

Thanks, If I can figure how to remove the clutch nut. I hate impacting wrenching against the gear box and my electric impact won't remove it anyway.  Any thoughts?

[Iahawk]

if you're talking about the big clutch nut (and not the nut that holds the clutch bell on) there's been a youtube video around for a while of a guy using a very large adjustable wrench...found it...

[Iahawk]

did a search for the different clutch springs...and found this

https://gy6motor.com/ncy-clutch-springs-2000-rpm-red-gy6

the problem is the engagement rpm...these springs say 1000 rpm for blue springs, 1500 for yellow and 2000 rpm for the red springs (linked above)...are there 'racing' springs with much higher engagement rpm?

[TBR125]

I was referring to the 17mm bell nut. The stock clutch springs are 1000 rpm. 3.6-1 ratio at idle creates 1000 rpm at clutch when engine is at 3600. I think my springs have weakened to approximately 800 rpm. Thanks for the link. I have decided to splurge and buy a full set from china. At least one of them will be what I am looking for.

[Iahawk]

good luck with the springs! You'll have to let us know how it turns out.

For removing the nut on the clutch bell I've had success using a home made clutch holder tool. Keeps the clutch from rotating then use a 24" breaker bar and the nut comes right off.  A piece of 1" x 1/4" x 24" bar stock works.

[Stig / Major Tom]

Thanks, If I can figure how to remove the clutch nut. I hate impacting wrenching against the gear box and my electric impact won't remove it anyway.  Any thoughts?

$12 clutch holding tool, ebay.
Cheater pipe on your ratchet handle.
Stig
...and can testify that impact gunning that big 39mm clutch nut is....pretty exciting.  Wear a helmet!....in case your Keds slip off.
M. Tom
...and as to spring question - here's where a good scooter shop would be nice to have as an info source. But we might be on the wrong continent for that.

[TBR125]

I found some good shops in India. Definitely the wrong continent.

[TBR125]

good luck with the springs! You'll have to let us know how it turns out.

For removing the nut on the clutch bell I've had success using a home made clutch holder tool. Keeps the clutch from rotating then use a 24" breaker bar and the nut comes right off.  A piece of 1" x 1/4" x 24" bar stock works.

Nice simple design. Beats trying to hold the bike upright with the rear brake clamped and operating the mega wrench with a foot.

[scooterfan]

I was referring to the 17mm bell nut. The stock clutch springs are 1000 rpm. 3.6-1 ratio at idle creates 1000 rpm at clutch when engine is at 3600. I think my springs have weakened to approximately 800 rpm. Thanks for the link. I have decided to splurge and buy a full set from china. At least one of them will be what I am looking for.

The original clutch on my Agility has a red spring - so I guess a red (performance) spring is actually the correct spring for all Agilitys. My Agilty does not have a rev counter - but I am quite convinced the engine revs were never higher that 3600 at take off.

I recently installed a new 125 / 150cc Chinese clutch on my Agility. I can't remember the spring color, but I decided to open the Variator and clutch setup during the next engine oil change for inspection. I will also have a look at the clutch spring color. As mentioned at another thread - unlike before my Agility's engine does not run slower and the scooter does not loose speed when I ride uphill in our area. I hope to find a way to compare spring tension, and will also have a close look whether the greased rollers are causing any problems.

If I find any difference I will let you know.

[scooterfan]

Oh sorry, you were obviously referring to the three inner clutch springs which holds the clutch pad arms.
I was referring to the big clutch spring, which obviously has nothing to do with at what engine RPMs the clutch will engage.

[TBR125]

I am surprised a red was used for the main torque spring. I hope red means something else in China as I haven't found stiffer springs than the red 2000rpm.

[dan v.]

The colors are - well, suggestive, and not really meaningful although many follow the same white, yellow, red scheme for some.   What is it - green, blue, black for some?  I think they all follow that 1000, 1500, 2000 rpm generalization.

More important is wire size and length.  Finding the proper size can be tricky. 

Install a proper set and try them out.  Change to the ones that suit you.  Having a tach helps in determining the take off rpms.

I've found Treatland to have a good selection of springs.

[TBR125]

Thanks for the link. The given rpm has so many variables that I am not expecting the springs to be accurate within 20-25% which is why I got several "for science"