Weight tuning a perf variator 50cc By twowheeler (Read 296 times)

[twowheeler]

Ive noticed a smoother transition in RPMS with a performance variator. A more consistant climb in the increase.

I tried 5gr sliders and the low to mid range rpms were mid 6s starting out to 7200 or so in the mid range. Seemed a little low and seemed to lack the power im used to. Changed to some 4gr Dr pulley sliders and I feel like the acceleration is perfect and pulls nice from the get go up to 40. My only concern is that at 40 plus im running 8000-8200 rpms but the acceleration from stop to top speed is great and rpms are in the low to mid 7000's up to about 30 mph then climb up from there towards 8000. I run full synthetic to try and get the most life from the motor as well.

Also why does a Znen made motor state max HP is at 8000 (BN139qmb) where a standard stamped 139QMB is rated top HP at 7500??? Everywhere i look for BN139QMB info lists it this way.

Here is a typical description:

Description:
1)Diameter of cylinder and distance: 39 x 41.5mm 2)Maximum power and relative rotation speed: 2.0kW/8,000rpm 3)Brand of crankcase lube: 10W-40 4)N.W:21kg5)displacement:49.6ml6)Brand of gear-box lube: SAE-90 7)Maximum torsion distance and relative rotation speed: 2.8Nm/6,000rpm

[Alleyoop]

Which Znen model do you have?
Alleyoop

[twowheeler]

B BOB

znen-motor.com/1-bob-scooter-1.html

[oldscootcoot]

I would guess the 2 horsepower ratings are max output and a rating for continuous usage. Several of the Lifan engines I have used were rated this way. When twisted to the max rating you have that HP available for short term usage.

Mix your weights

[jct842]

Wish since they went to the trouble to print it in English wish they would put the specs in English too since it is for sale here. Metric to me is like a foreign language I do not understand. If you used metric every day no problem, but comparing the two...........I know what a foot or an inch looks like but visualize how long the 1285 mm wheel base is .

[twowheeler]

at least the rpms numbers dont change