CVT questions/weights/belt/clutch By mheinemeyer (Read 3,906 times)

[mheinemeyer]

I have a 157QMJ-A engine. I would like to tune the CVT.
I have 18x14-15 gram rollers stock. The belt is 835/20.
Here are my questions.
What would a belt change out do? 835/20 to 842/20
What would a teflon variator do and is 115mm important?
Going from rollers to sliders?
From other threads, I see most go from 15 g rollers to 12 g.
If I go to sliders, do I need to adjust the weights?
Going with a performance clutch...is it worth it and if so should I go with a 1500 torque spring and medium clutch springs?

My objective: My take off is a little slow. Top end is around 62mph. I would like a little studier takeoff and keep the top end fairly close. I do have a few hills, so maintaning speed is crucial.

Not asking for much am I? This might take it over the top... anyone have a million dollars they would like to send me?HA

[mheinemeyer]

Forgot to add... It was above 40 degrees here in Iowa so I did get the scooter out today. I currently have close to 25 miles on it.

[Alleyoop]

Hi Mheinemeyer,
I also have a 157QMJ motor on my PST150H Trike. Is 62Mph GPS or are you going by what the Chinometer says. Why I ask is that most 150s will do 50s and not in the 60s without some mods does yours have 13" tires, if so that may explain it.
If you are getting in the 60s I would not touch a damn thing:) But if you want to get a little more out of it you can tune the CVT a little better.

But anyway you have the Long Case 157QMJ due to the belt size it takes.
My 157QMJ is the Short case which takes 743-20-30 belt.

The longer belt will allow the Belt to Climb higher in your Variator for "MAYBE" 1-2 mph faster depending if the belt reaches the lowest point in the Clutch Pulley. Sometimes with a longer belt you will loose top end due to the belt NOT dropping down low in the Clutch Pulley.
Only way to find out is put the longer belt on and try it.

Weights:
I also use 12Gram Weights in mine as well. You have to experiment with the weights to find which combination you like, again it is all how you want your scoot to run.

A Teflon Variator is not all cracked that they make it out to be.
A 115mm Variator is a GOOD BET unless your Variator is already near that size Diameter.
Take a Look at your Variator and see if it is smaller than your Front Pulley(FAN) plate. You can measure your Variator across and if it is the regular size it will be around 105-107mm in Diameter. So a 115 Diameter Variator will allow your belt to Climb another 1/4 of an inch higher than with your smaller Variator. Don't forget the Higher The Belt Climbs the More MPH you will get(as long as the belt reachs the lowest point in the CLutch Pulley).

Getting a Performance Clutch is Not a Bad Idea, they have a lot more PAD length about an inch more on each Pad. That grabs the Bell more and less slipping will occur.
Putting in Stronger Springs yes you may Jack Rabbit off the start but your RPMS will be very high.

Here is how the spring numbers work:
Say for example right now when your RPMS get to 3000 your scoot starts to move.
If you add 1000 spring your scoot will now start to move at 4000 rpms.
If you add 1500 spring your scoot will not start to move at around 4500 rpms.

The spring numbers are the extra RPMS required over the OEMs. So say you currently go around 30-35 and your rpms are 4000 or so with stronger springs your rpms will be 5000 or higher at that same speed. I don't think you will like them because you always need to keep the rpms up. Most buy them and take them off and put back what they took off.

The most I would put on with the Performanace Clutch is a 1000 Contra Spring for quicker take offs, that will not raise your rpms to badly. You can Also control your rpms with the Weights:

Heavier Weights require less RPMs to throw them out to close the Variator to push the Belt up the Face. If to heavy your starts and mi-range will be sluggish due to the Belt being pushed up the Variator to Fast past the lower gearing range of the Variator.

Leighter Weights require higher RPMS to throw them out to close the Variator to push the Belt up the face. If to light your belt may not climb up high enough for a good top speed because the are light they will stay in the lower part of the Variator giving you great starts and mid-range but you may loose top end.

So that is why you need to get different Gram weights and experiment and find the ones that give you good start and mid-range and good top end.

From you are saying you do need Lighter weights for the hill climbing and such.
I would get 12s and 13s:
You then can try:
1. All 12s
2. All 13s
3. 3-12s and 3-13s for a combo of 12.5
4. 3-13s and 3-15s for a combo of 14.
I think one of the above will meet your needs.

Sliders do not get them until you find which Weight Grams you Like reason being they are TWICE AS EXPENSIVE. Then when you find the Roller weight Gram you like then you can get SLIDERS(but get 1 Gram Heavier than what you decided with the Rollers).
Here is the Reason behind that:
Rollers will change your RPMS by 500-600 up or down for every gram you change.
Sliders will change your RPMS by 200-350 up or down for every gram you change.

So as you can see going to 1 Gram Heavier when you go to the Sliders your RPMS will be almost the same as with Rollers that are 1 Gram less than the Sliders. So what you just did is went up 1 Gram more than the Rollers they are heavier you get a little bettet top end and your rpms will be almost the same.
Alleyoop

[Cruiser]

I would get a few hundred miles on the scoot to let it break in. The performance will improve after break in. Keeping the OEM weights in will help hold the engine rpms down for a gentler break in.

You should be able to do what you want with just a change to the lighter slider weights. They are a straight swap with the roller weights. Remember to clean out the variator if there is any grease in it. Slider weights require no lubrication. The advantage of slider weights is that they allow you to go light for better acceleration while maintaining most of the top speed because of their peculiar shape.

[mheinemeyer]

Thanks alot Alleyoop and cruiser. Alleyoop, Thank you for that detailed explanation. That was absolutely wonderful. Cruiser, you make a good point. Maybe I will just buy the rollers to start and break this baby in. OH...Alleyoop, Yes that speed check was with the chinometer. I probably can back that speed down 8 mph or so. We will not have good weather again here for at least a week so I will just order rollers at this time and wait for better weather even though it might kill me. These things are alot more fun than motorcycles and quite frankly, alot more comfortable. I have to laugh though....20 years ago, I wouldn't have been caught dead riding one of these scooters.

[mheinemeyer]

And by the way. Because of your great info, I just donated to this site. The owner of this site has you....Alleyoop and cruiser to thank for that. Oh...Alleyoop, When I was researching on where to buy my sccoter, I ran across a website that has that same picture of your trikes.
I want to say it was a florida company but I can't find it again. Do you know what that was?

[mheinemeyer]

Also, My variator is a 105. I think I will order one of those 115 variators and maybe the performance clutch with 1000 torque spring. I can't help myself. Someone stop me!

[Alleyoop]

Mheinemeyer,
If your going to get a Performance Variator get the PRODIGY they are top notch quality and some of us on here have them on. I have had mine on for 2 years now it is great. They run about $20.00 more than the others but you will not regret it.
Let me ask this are you looking at this Variator:
www.scrappydogscooters.com/125_150cc_Performance.html

If you really want that one I will sell you the one I have, I got it put it on tried it and took it off and put my Prodigy back on. I put it back in the box it came in. Sell it to you cheap+shipping.
I did not like it compared to my Prodigy Variator.
Alleyoop
This is the Prodigy:


Here is what the difference is in size:

[Cruiser]

We are very happy to help you out. Thanks for the accolades. It looks like you have the scooter bug for sure. Try to keep a journal of all the upcoming tweaks on your scoot so that the rest of us more timid types will be able to gain from your experiences. It would be interesting to see how these aftermarket products work and what your opinion of them will be. Keep on having fun with your scoot.

[Kaveman]

I have an MRP branded variator assembly ( was purchased to replace stock variaitor ) . Have you had any expierence with any of their products ?
Bill C.

[Alleyoop]

No, I have not, their parts are rather pricey.
Alleyoop

[mheinemeyer]

Hi Alleyopp... This is the variator I was looking at... www.monstergy6.com/product_variators.htm#5
Or the one from kidnme.
Where do you buy your Prodigy variators? I did a search and found info but not a place to purchase?

Cruiser... I will keep you posted on how things progress.

[Alleyoop]

They are hard to find and far a few to be had, they usually run little under $100.00 bucks. I googled and did not get a hit on someone that had them.

Maybe the google master Jrryan can get a hit.
Alleyoop

[mheinemeyer]

I hope to post some videos later or at least a link.

[Cruiser]

Here is a Prodigy branded performance variator from Motori tec:

www.motoritec.com/product02.php?nID=43&page=1&fID=42