Super Dio ZX AF28 and other Dio scooters

[bakaracer]

what is the air fuel screw at?

[sanjuro]

I haven't touched it at all, but I can check tomorrow. Where is it located because the last time I looked for adjustment knobs, I only saw the idle speed wheel?

[bakaracer]

on the mikuni its the screw that is recessed in next to the mouth of the carb.

[Wheelman-111]

Greetings:

On the Mikuni, the AF screw is on the inside of the carb throat, coming up at a 30-degree angle upward and to the right side, in a little socket-shaped tower. It can be reached awkwardly using a hex-drive flat screwdriver bit held between the fingertips, almost up against the tire. Start at about 2 turns out with that giant 40. :p

[sanjuro]

Thanks, I'll get it done.

[sanjuro]

Start at about 2 turns out with that giant 40. :p

Well, that did the trick. No more of this funny 'on throttle' response when I let off of the throttle at 30 mph. This morning I did do some acceleration runs up to 40 mph, and the bike pulls cleanly all the way through. I'm kinda shocked at how linear everything is. I will do some more break-in riding before tuning the transmission to take advantage of the pipe, even if it's milder than the PG Long.

[Wheelman-111]

Greetings:

Glad you got it going sweet, but curious: At how many turns out was the screw set before? And so the 40 doesn't blubber right off idle?

[sanjuro]

The mixture screw was set at 2 1/4 turns before I adjusted it based on your recommendation.

...and no, I don't get any of the blubbery carb response. It's real smooth and crisp.

[bakaracer]

do you have a temp gauge?

[sanjuro]

No temp gauge as of yet.

[sanjuro]

Just finished the latest 20 minute ride with the following: 40 slow jet and 175 main jet.

I hit 70 km/h (43 mph), and the scoot had plenty left, but of course I backed off very quickly. Still no bogging or stumbling, and everything seems so smooth and effortless. I'm also beginning to think I have the 8.4:1 gears installed instead of 9:1 because I've turned the clutch bell 8.25 turns for every 1 revolution of the rear wheel. I thought I counted the gear teeth right, but who knows until I open up the transmission and recount.

So, how fast do you think this bike should go with the cast iron kit, pg typhoon, and 8.4:1 gears?

Last of all, this thing goes through fuel very quickly.

[sanjuro]

I just got off the phone with Keoni of vtcycles and learned something new today. When you order the 9:1 secondary gear set and have a Dio ZX transmission the gear ratio is not 9:1. By my calculations it translates to 8.25:1.

The reason this occurs is the kit that vtcycles sells is for the U.S. Elite transmission, which features a 12 tooth primary drive shaft with 42 teeth on the larger cog of the countershaft while the JDM Dio ZX uses 13 teeth on the primary and 41 teeth on the corresponding cog of the countershaft.

SA50 (Elite SR 12:1 gets converted to 9:1 using the secondary gear set from vtcycles)
PRIMARY DRIVESHAFT (12T)
GEAR (42T)

SK50 (Dio ZX 11:1 gets converted to 8.25:1 using the secondary gear set from vtcycles)
PRIMARY DRIVESHAFT (13T)
GEAR (41T)

[bakaracer]

with those gears and your setup 60mph no problem topspeed.what are you premixing your ratio at?

[sanjuro]

...what are you premixing your ratio at?

32:1

Should I stay there or change it up?

[bakaracer]

...what are you premixing your ratio at?

32:1

Should I stay there or change it up?

32to1 is ok but to be a little more safe 30to1 or 28to1 but you will have to rejet if you change your mix ratio since your jetting now is to the mixture you have now.