Acceleration Problem / Yamaha Jog

[90GTVert]

It's normal to take a while to fill the system with a vacuum operated petcock. You can fill the bowl, do as 54cc says and apply a vacuum till the lines fill, or you have to crank it till it fills enough to start. Yet another reason I like manual fuel shutoff valves is that all you have to do is open the valve and the bowl/lines fill as long as the tank is above the carb and fuel lines run steadily down hill.

[tsimi]

Could i connect any carb to my scooter as long the diameter of the intake part fits?

And would a 68cc BBK run with a stock carb?

[birdman]

68cc BBK will run great with stock carb, all you need to do is install a larger mainjet.

[tsimi]

small update on the situation. (just in case someone is interested)

After removing the main jet (#72) and putting back the stock one (#68) i didn't get any difference in speed, response or acceleration. I then tried roller weight combinations from 6x 5g, 6x 5.5g, 6x 6g or 3x 5g + 3x 5.5g. Nothing changed to the better. I either get good take off and slow mid-top end or slow take off and good mid-top end. but nothing balanced that would go all the way from take off to top end.
So i decided to revert back to the stock Variator with the settings i had (3x 5.5g 3x 6g and 2 shim washers total). First thing i realized is the sound of the Scooter is more high pitched in idle mode with the OR Variator i had more like a 5.7l V8 muscle car sound.
The take off is great thanks to the 2 shim/washers acceleration to reach top speed is also steady with a tiny drop at around 20-30km/h top speed is of course lower (around 67km/h)

Not sure but i think the stiffer torque spring and the new OR Variator don't harmonize together no matter what the roller weight combination is.
I should get my second Jog by the end of the year and then i will be able to easy swap the clutch assembly. I then will try it again with a stock torque spring and also will upgrade to a more stiffer spring (10% up, red colored) and see how that goes.

[tsimi]

It is an old topic but I thought I'll give a small update as to how it is at the moment.
I had issues in the past when using an after market Variator with steeper surface and flat center surface as seen on page 5.
When I had the 50cc engine I needed to counter the stiffer torque spring by adding a bit heavier rollers, that was the theory that time and I thought that I could use the same setting for the OR Variator but that didn't work. After multiple tests I gave up on the OR Variator and went ahead and installed a 70cc BBK.
Now with a 70cc we have a total different ball game. I added a more stiffer torque spring (now 1500rpm) and I kept the same Stock Variator setup (3x6+3x5.5) and it runs strong because of the BBK. Last weekend I thought I give the OR Variator another try but this time I did some homework and researched about it especially the steeper surface issue. And it says when you have steeper Variators you need more rpm or centrifugal force to move the belt up so instead of going heavier to counter the torque spring I ignored that and added 6x5 rollers and the result is pretty impressive. Now not only do I have a stronger takeoff but also a faster acceleration and top speed. The OR Variator in combination with the power of the BBK seem to be just perfect partners.
I will keep this setup for now and see how it behaves in daily traffic.

So here again, theory is heavier rollers to counter stiffer torque spring but this works not when the Vario has a steeper angle. If the Vario has steeper angles ignore for now the torque spring theory and just go light on the rollers until you get into the power band when driving.