Well, It looks like it is my turn to have problems with the J Costa variator. I had recently noticed a drastic drop in my gas mileage (to only 40 mpg), so I was concerned. Then, when I took my bike in for the 20,000 Mile service today they found scoring on the faces of the variator plates and an oil leak in the rear unit. I know that several others on here have recently had problems with their J Costa variators and had switched back to the Honda original equipment with the Dr. Pulley Sliders. I think that is what I want to do (at least for now). Do the sliders come in different weights? I wanted to ask you guys what combination of slider weights would provide the best combination of good gas mileage and acceleration. Any suggestions?
Thanks
DCC

I went back to 28g dr pulleys and didnt like it at first but now I like it

I was just wondering if my J-Costa could be re-surfaced on my small lathe....Well here it is and it fits....So I Got her done. I took a short video of the variator turning, Sorry, no sound, I must of had my big fat finger over the mic on the camera.

Set my lathe at 14 deg's and just shaved the high spots down on the surface.

http://www.youtube.com/watch?v=MaL4RaWM56c

good job Dennis!!!!!!!!!!!!

MaxB

Ok, Now I know...The sound is not working on my old laptop. That's the reason of no sound when I loaded this video up. Just something else to work on. O'well.

Hi Dennis.
I assume you didn't machine much off the J. Costa sheave, maybe a couple 'thou?

Are you going to reinstall the J. Costa and try it again?
My simple way of thinking suggests that after machining there will be slightly more space between the sheaves. That would cause the belt to ride lower, increasing the reduction ratio and making the engine turn slightly faster. Acceleration should increase slightly as well as rpms across the power band at the expense of fuel consumption over a stock J. Costa. Top speed might increase as well. I'd be very interested in the results if you try it.

bigbird,

As a Designer, stacking up tolerances is what I do best.

Just shaved the high spots down and dressed the new surface with a little light emery cloth. Also took off a little on the end of the J-Costa's center hub so the Honda part of this drive will move over a very small amount to compensate for the material I removed off the J-Costa's drive surface. I was thinking of installing a thin spacer on the Honda drive shaft to bring the entire drive assembly over just a little. This may not be needed. I'll look at it when I get in to it.

Thank you for taking an interest in is project.

Well, I re-installed the J-Costa today after the face refinishing of last night and taking off 50 thousand off the J-Costa's Center slider barrel, this morning. I also did a little experiment...I placed 1.5" long x 3/8" very light compression springs under 8 of the 16 pins and went for a ride.

I really love how much smoother the J-Costa makes the scooter fell at take off.

OK, here it is, at 70 MPH indicated the RPM's were at 5.7K. A bit better than 6K when I removed it a while back.

The purpose of the springs was to up the outward pressure on the pins at low to mid range speeds. When the Pins reach the full extent of their travel, at high speeds, the pressure on the pins becomes less. I think it worked! Since I purchased all 8 of the #6 compression springs Ace Hardware had in stock today, I will need to get 8 more springs and do a full test on this soon...So more to come.

Very interesting, Dennis.
At 70 mph indicated my Swing with J. Costa shows 5300 rpm.

I was out this afternoon on probably our last nice Fall day and did 80 miles. The temp peaked at 60F, but it was a very cool feeling 60F. I had on a T-shirt, long sleeved fleece, and my Joe Rocket armored jacket with the liner vest removed and I was comfortable.
I had on my blue jeans with Joe Rocket armored pants over top. Again, very comfortable. If it had been summer and 60F I would have been par-boiled in that getup.

By Wednesday the forecast high is 38F. I'll wait until the fat lady sings (permanent snow) before I change the oil and put the Swing to sleep for the winter in my garage.

Dennis:
I am very impressed with your ability to resurface the faces of your J Costa and I am curious how the reworked J Costa affects the performance (acceleration) of your bike. Does it feel as quick as it did before? Is it quicker that it was with the sliders?

I really just love the power and the smoothness of the J-Costa Variator and the only fault with it is the aluminum that they use is a little softer then what Honda uses. They should have machined a replaceable steel disc face into their drive.

This taking down the high spots and shorting the barrel did help bring the J-Costa back from the grave for me. I think it's something worth doing when the J-Costa starts to act up. I'm experimenting with using springs to push the pins out with a little more force for more mid range power with better fuel mileage is what I'm after.

Get a set of sliders and give them a try. I really like the J-Costa over the sliders.

Well...I gave it a try. After running the J-Costa with the turned down drive plate surface and soft compression springs under 8 of the pins it turned out that I will need to remove more material off the end of the barrel and place a spacer behind the J-Costa to move it out so it will line up with the driven face. I'll try this when I get a chance this winter. For the time being I went back to the original Honda variator and rollers. FUN, FUN, FUN!