Yuminashi variator and belt

[Mgalutia88]

So changing the backing plate back to the honda part netted a less than 1mph gain and moving around the shim did nothing for top speed. I'm going to switch back to my stock exhaust next to see what happens?

[wingz]

Changing exhaust shouldn't do anything to rev limited top speed.

[wingz]

Can you please make a video showing the position of the belt when at top speed?
This will give us an idea of how much unused pulley is left to increase the gearing.

[Mgalutia88]

The NCY video was with 13g rollers. Changing exhaust does not change the rev limiter you are correct. It does however change the tune with the variator. It means I probably need lighter weights to correct my issue; pending top speed changes with the stock pipe.

[waspmike]

Paint the pulley with a blue felt tip marker, 3 or four one inch strips should be enough and the boss. The belt will rub off the blue where it touches.

[waspmike]

Can't edit above:

Are you on the stock IRC tires? Or a different brand?

[Pcxdemon]

So you got 132kmh with yumi vario? Is you speedo accurate,if it is than thats all you going to get from it..To get that speed for me id need to be showing some 145-150kmh on the speedometer what you normally see in the Yuminashi vids,so their real gps speed is around 130kmh gps real speed.

Also,i got yumi belt here and its few millimetres longer then stock size belts and that also may play part with yumi vario performance...

[wingz]

Also, the engine in the Yumi video revs over 10000rpm.
I haven't checked how high mine revs.

[waspmike]

Also, the engine in the Yumi video revs over 10000rpm.
I haven't checked how high mine revs.

I met a guy in Bangkok whose old PCX did 140 kph. It was pulling over 11,000 RPM. Which sounds about right if one works out the gearing based on stock RPM limit and speed attained at that limit. But you'll need over 20hp

If you use the 10,000 numbers a stock bike will do 120 kph at the 9300 limit at 13.5 hp. If it won't get to 9300 then it needs an after market non CAT exhaust to release another 1-ish hp more! My formula is not perfect but it gets refined with each additional bit of info.

Rider's weight makes a difference as well. Difference between a 100kg rider and a 70 kg rider is about 5 kph on the flat. (based on numbers for a new 125)

[HawaiiJ]

Also, the engine in the Yumi video revs over 10000rpm.
I haven't checked how high mine revs.

I met a guy in Bangkok whose old PCX did 140 kph. It was pulling over 11,000 RPM. Which sounds about right if one works out the gearing based on stock RPM limit and speed attained at that limit. But you'll need over 20hp

If you use the 10,000 numbers a stock bike will do 120 kph at the 9300 limit at 13.5 hp. If it won't get to 9300 then it needs an after market non CAT exhaust to release another 1-ish hp more! My formula is not perfect but it gets refined with each additional bit of info.

Rider's weight makes a difference as well. Difference between a 100kg rider and a 70 kg rider is about 5 kph on the flat. (based on numbers for a new 125)

What was the Bangkok guy's secret to doing 140 kph?

[Mgalutia88]

The big thing that I noticed is that my rpms were lower. That was the main thing that clued me to try swapping the stock exhaust back on. Yes Pcxdemon my speedometer is accurate. Btw, does anyone know what torque spec the exhaust manifold is tightned to?

[dasshreddar]

thanks for the test, where did you get the yumi variator from?
and that video was with the 13g sliders?

What sliders/rollers did you use in the yumi video?

[wingz]

Sounds like 9500rpm limit.

[Mgalutia88]

I was using the yuminashi supplied 12g rollers. I fitted the stock exhaust back on and found a 1mph loss in top speed. So 80mph.

Cruising on the highway today I found that I could run at least 70 mph against our 20mph winds and I hit 79mph down hill. The scoot feels like it is much punchier all around. At higher rpms there is still power. Reapplying the throttle yields strong acceleration. I'm goin to wait now to hear back from masato on the 16th about how bi a difference their belt might make. In the mean time I'm thinking about pcxdemon's intake setup. Maybe a kitaco rear gear.

[dasshreddar]

I was using the yuminashi supplied 12g rollers. I fitted the stock exhaust back on and found a 1mph loss in top speed. So 80mph.

Cruising on the highway today I found that I could run at least 70 mph against our 20mph winds and I hit 79mph down hill. The scoot feels like it is much punchier all around. At higher rpms there is still power. Reapplying the throttle yields strong acceleration. I'm goin to wait now to hear back from masato on the 16th about how bi a difference their belt might make. In the mean time I'm thinking about pcxdemon's intake setup. Maybe a kitaco rear gear.

Great, now where can I get that yumi variator from?

Do you have sliders to test with the yumi vari? 80mph is plenty for me, but I would sure like to get to 65 as easily as I can get to 55.

[Mgalutia88]

I do have sliders however the texture inside of the variator would shred sliders. It's coarse for a reason. Pcx racing carries the variator. It ran about $175 with shipping from france

[waspmike]

What was the Bangkok guy's secret to doing 140 kph?

We'll assume it was indicated!

I wrote it all down at the time. I'll dig out my note book. But from memory

160 conversion on old 125
CBR250 valves
Extra strong valve springs (stock Honda parts)
CBR150 Throttle body
API ECU
OVER Exhaust (from the picture Sept 2011)

Tire looks larger but I didn't check, at the time.

If I missed anything I'll post again.

[waspmike]

Apologies it was only 130 but it was a while ago Sept 2011.

[dasshreddar]

I do have sliders however the texture inside of the variator would shred sliders. It's coarse for a reason. Pcx racing carries the variator. It ran about $175 with shipping from france

I couldn't find the yumi vari on their website it's a "Speed Booster Variator V.2013" right?

[wingz]

I can't get their website at all today.