JCosta vs Dr Pulley sliders - specific questions!

Reading what you wrote, I'm gonna say you should have bought a faster
scooter in the first place.

I don't want to blow the engine up running the bike at 7/8 of it's available
revs at all times. Don't want the fuel consumption that comes with it,
don't want the noise either.

Just want a smooth, relaxed ride, and the CVT (which is a huge compromise
to begin with re: delivering power to the ground) that's setup as good as
possible.

There is a fellow on totalruckus in the Big Ruckus section that has tested about every weight roller/slider combination in comparison with the jcosta. He plotted the results for reference.
http://totalruckus.com/phpBB3/viewtopic.php?f=28&t=27877&hilit=jcosta
I think the answer you seek is there, good luck with the data.

I would agree with you on that , except for the fact that I am not taking off full throttle all the time .
On the Big Ruckus the jcosta smooths out the flat spots , on the Tmax it just plain makes it even
faster on take off than it already is . If you are looking for an excuse not to buy one , you don't need
one . Stick with your same variator and play with the weights . I did that and like I said found it to be a waste of time and money . I don't care about the money spent on the jcosta or the fuel , I care about performance first .

Excellent reference, thanks Warney! Perfect!
There you go Cortez, someone HAS done the tests!

Not sure on my top speed. Took me and my wife (both of us are approx 320lbs) on a run at about 80mph. It didn't have any problem and had a little left. It was mostly flat. I've hit 85 without any issues. The way it feels I don't think it would have a problem hitting 90+. However, the bike didn't come into it's power until somewhere between 1K-2K miles in the break in.

Let me know if you try one of the things mentioned here. I have to admit, that the 300i feels like it's in a sweet spot, so the gains would have to be something pretty noticeable. And price isn't an issue, the improvements just have to be worth the price.

Cortez- The reason no one has answered your question, is because it is not a cut and dried one. There is no simple answer to your question.
This is the basic rule for scooters: The lighter the roller weight, the quicker the acceleration, but lower the top end and higher cruising rev's. In reverse, the heavier the weight, the slower the acceleration, reduced cruising rev's and potentially higher top end. These are rock hard rules to a point and that is why I question the 30+ horsepower. New rule: Torque= acceleration, Horsepower= Top end.
For the most part scooters are very efficent. They are designed to operate in a certain rev range and the cvt was balanced to operate in that range from the factory. They are trying to remove or limit the input of the rider. From the factory, that scooter is the best it can be at doing everything it was designed to do. You will not do better than the factory, if you change their set-up, you will have to give up some thing, ie.. fuel mileage, top end, bottom end, but it will be something.
Remember I said the rules were rock solid to a point. You can go too light on the weights and too heavy, neither is good. Too light and it just rev's and the scooter has very little go, too heavy and it bogs and has no go. The easiest place to learn to tune a scooter is with a 50cc 2-stroke because it operates in a narrow power band at high RPM's. The reason I say it is easy is because little changes make a big difference both good and bad quickly.
Now to answer the question you have been asking. You went the wrong way with the Dr.Pully slider. You need to go up 2 grams above the stock roller weights, so if they were 15 grams, you need to go to a 17 DP. You should have a little better acceleration and your top speed should come back.
Oh yea, why I questioned the horsepower on your scoot. The change to the variator weight that you did should not have changed the top speed that much, if you really had the horse power to pull it.

Good luck

Thanks!

Yeah, about the bolded part, I would have kept my Kawasaki if I wanted
that, but I value smoothness and other stuff more now.

Getting old, I guess.

+1

Will do!

Never figured there's someone that'll do that, but I would.

I've got a Silverwing that I put a J Costa on in January of 2010. I've put 16,000 miles on it since then. I replaced the pins last year (about 9500 miles on original pins/rollers) and replaced the belt at the same time. In February 2012 (just about 700 miles ago) I installed a HiT clutch. I also own a Vespa GTS, and I installed Dr Pulley sliders last Fall sometime. Most of these comments are regarding the Silverwing/J Costa; I mention the Vespa solely to show that I have some experience with DP Sliders.

What I recall about the J Costa is from memory and not written notes, but is probably accurate.

With the J Costa, the Silverwing runs at higher rpm's under any acceleration - whether from a standstill or at cruise. It would hit 6800 rpm at WOT (peak horsepower is about 7000 rpm) and hold it there until about 60 miles per hour, at which point rpm's would drop. Most cruising speeds would be about 5000-5500 rpm's (peak torque is about 5000-5200 rpm). With the JC, there is a distinct drop in rpm's once you back off the throttle and cruise - about a 1000 rpm drop.

With the original rollers, acceleration under WOT would jump to about 5000 rpm's and then climb if your speed went high enough (memory is foggy, but probably above 65/70 mph). If you accelerated more gently, the rpm's would be about 3000 rpm's and climb slowly towards 5000 rpm's. There is a common feeling among Silverwing owners that this was a cause of vibration and rumble on a stock Silverwing.

In both cases, cruising speed rpm's would end up around 5000 rpm. Generally, the JC would cruise about 200 rpm lower than stock rollers. But, if you snap the throttle open, the JC would allow the rpm's to jump 1000 - 1500 rpm to get near the HP peak. Stock rollers would not change their rpm much at all - it depended upon torque to accelerate.

Regarding the Vespa with DP Sliders - they are 10 gram Sliders vs. the 11 gram stock rollers. Generally, they cause more rpm most of the time, but have given me more snap off the line. Top speed does not seem to be affected - after installing a new belt about 250 miles ago, my top speed was about 76 mph with my larger, cold weather screen in place. That is a good top speed with that screen for that bike. My gas mileage did not change much - maybe 2 mpg less than I used to get. I get about 65 mpg in the colder months, and 70-75 mpg in warm weather. I take more long trips in the nice weather.

I want to warn you about a few concerns with the J Costa.

First, my mpg probably dropped 2-3 mpg with the JC (from about 50 mpg to 47/48 mpg when it was first installed). However, as it wore, miles per gallon slipped a little, even after installing the new belt and variator pins.

Second, the variators wear out. The pins get about 8000-10,000 miles before they cause the rpms to run too high all the time. Also, the brass bushing in the center of the variator is impregnated with graphite which is supposed to lubricate the bushing. By the time I had 9000 miles on mine, the rpms were very high. Upon disassembly, I found the bushing was very sticky and would not slide left/right on the crank shaft collar very well. I cleaned it thoroughly and installed new pins/rollers and it worked well for about 100 miles, then began to stick again (I saw rpms up to 8000 a few times). I disassembled it again, cleaned it, and had the same thing happen (100 miles then sticky). The third time around, I lubed the brass bushing carefully with a drop of synthetic motor oil and got about 2000 miles before it acted up. Last time around, I lubed it with high temp wheel bearing grease and it is working well (but for how long???). It's getting to be high maintenance.

Third, when the pins wear, and your belt wears, the two halves of the variator can get too close together and grind away at each other.

Finally, a friend who also has a Silverwing with a JC said that in addition to the same problems I've had, he only got less than 6000 miles on a new belt he installed (while using the JC).

All of this adds up to enough problems that I will be installing DP Sliders before the year is over. The JC is an absolute blast when it works well, but they tell you in the instructions that it is a race part and not expected to be used like a stock part.

Regarding the HiT clutch - I bought it because I had a good year last year (financially) and said WTF. It works mostly as advertised - it allows rpm's to climb higher before the clutch engages, so there is less lugging of the engine. It also locks up the clutch to avoid slippage when you accelerate while already cruising. Installation was easy. Acceleration off the line is better, and cruising speed acceleration is slightly better. All of that is fine, but I would only recommend it to someone with excess disposable income. I do not believe you will get better gas mileage with the HiT clutch, so there will be no monetary savings.

If you have unlimited funds, then buy them both (J Costa and HiT clutch) - they are fun but not earth shakingly fun. If you don't have unlimited funds, then I would suggest spending your money on the DP Sliders (which I think you said you already have done). The J Costa does cause rpm's to climb under acceleration and to reduce while cruising, which is what you are looking for. But, the J Costa is quite a bit more expensive than the Sliders, wears quicker and makes for more maintenance. And you will never save enough in gas to pay for either the JC or the HiT clutch.

Hope this helps, Cortez. Or helps somebody else.

Sure there is.
Just need someone who remembers how much the engine used to rev before
he swapped over to jcosta, then repeat the process, at normal riding speeds.
It's very simple.

Um, actually, you're wrong.
There's A LOT of people on kymcoforum.com who tried different slider
weights, and even the dr pulley folks recommend going 10% lighter then
stock to MAINTAIN the same top speed, and gain acceleration.

The 17gr sliders would result in even lower revs after 60mph and the
scoot would actually be even slower, since it would have even less
power at those revs.

The guys who get 100mph indicated out of their Downtowns are usually
using 13gr sliders and a few other mods since that weight allows the scoot
to reach 8000+.

The horse power we're talking about is achieved at 8000 revs, which I can
no reach with this setup, and heavier weights would make it even worse.

Thank you FoldArt, this should be a 'sticky' post, it's a great review of what's
going on.

I guess you're right, I don't have $$$ to throw around or I'd just buy it and
try it, and I'm obviously asking around a lot..

The 15.5gr stock to 14gr DP slider upgrade did wonders already, and I should
just stick with that.

I value reliability above everything else since I tend to do long rides..

Thank you very much!

Now.. when will someone make an aftermarket eCVT (burgman 650 type stuff)?

Check this out:

http://majestyusa.com/forums/viewtopic.php?f=27&t=9250&sid=79e218cd71df486f8d5fda4b1ae90086

Glad to be able to help.

PS I have recently given up on the JC. Tried 24g sliders, now using 21g sliders. MPG with 24g was 55.1 on 255 mile trip, but acceleration mediocre. 21 g sliders have good acceleration (almost as good as JC, but not quite). I will see what kind of MPG I get in two weeks.

I can now already guess that kind of stuff when I see the revs I'm at.


There's a huge difference in fuel consumption on mine between 70 and
80 mph (about 20%), but I love that my sliders took the cruising revs
down by about 500 revs at speeds over 65mph or so.

HOWEVER, with a huge-ass windscreen and a huge-ass top-case, the
bike will now top out at 81-82mph, NOT GOOD for a 30hp bike!

At that 81-82mph top speed (83-84 if I'm lucky), the bike is running at
7300 or so revs, and the damn thing has it's maximum power output at
8000!

Good thing is - I can probably run it at those revs 24/7 if I wanted to..
the bad thing is, I want the rest of my 3-4hp back, damnit! If I wanted
a 250/20hp bike, I'd get that!


Going down one size (weight) with the sliders may fix that, but then again,
I may end up with the same top speed, at higher revs, and then I'd probably
shoot myself in the knee. Acceleration would be even better, but I'd be
looking at 2/3 of available revs just chillin' around town, which is, again, not
good.

Did I mention I want Burgman 650's se-CVT yet?
SOB.

Excuse the rant.

On the plus side, the bike is a joy to ride between 40 and 70mph.
I just need that "power" button to make it rev more when I want it to.

Lemme close the Malosi Multivar page while you tell me that I shouldn't
have sold my bike (with 6 gears).
:huh

Speaking of Malossi Multivar..

Can anyone tell me (since I'm not able to figure it out by myself) what the
hell does it do different to any stock CVT to make it that special (read:
expensive)?

Most people answer: "It'll make your bike accelerate faster!"

Fine.
I can do that with the stock CVT too, just use different weights
and/or sliders.

I can mess around with springs to alter the launch revs too on the
stock CVT, so it's not that either.

I don't want to make a screaming racing scooter out of this thing, but
it would be wonderful if wide open throttle would pin the revs to 8000,
so I can use the damn 30hp I paid for, and not have 7000 revs cruising
at 40mph as a side-effect.

From what I've read on CVTs in the last few years.. this is not possible
without the SE-CVT or a similar system.

Someone better prove me wrong.
Right now, please.


p.s. Did I mention I had a stock People 300GTi (2hp down on Downtown,
and about 50lbs less) virtually up to 100mph? Stock!

Too late!
You people suck at talking other people out of idiotic decisions!
So I just ordered the Malossi Multivar 2000.

TAKE THAT!


Given the videos on the youtubez with that setup, I'm probably gonna have
to go the Dr Pulley slider route with this guy too, we'll see what happens.

The stock weights are 23x18mm, 21gr, 6 of them.

Stock variator had 6 of 20x12mm, 15,5gr weights which I replaced with
14gr sliders.

Glad to be able to help!

We'll see how that goes!