Can anyone tell me what the Silverwing engine RPM is normally on a stock 2003 Silverwing at certain speeds..say 40 mph, 50 mph ,60 mph 70 mph etc? I have a new (to me) 2003 and am curious. Is there a chart or link some where? Thanks.

It depends on several factors.
1) The stock speedometer is not accurate. It is about 10% optimistic, especially the faster you go.
2) Belt condition. A worn belt will show higher rpm for a given speed than a new belt
3) Modifications. A different variator, sliders, rollers will all affect rpms, some increasing from stock and some decreasing.
4) Load. If you're pulling up a hill or accelerating, your rpm will be higher at any given speed.

As a general rule of thumb, 60 mph indicated is about 4500 rpm, and 70 mph is 5000 rpm, + or- a couple hundred rpm.

Elkk:
As mentioned by Bigbird, the speed vs rpm ratio depends on several factors. I just got a new 2009 in June and have been fixing it up to better serve my needs/wants. I used to have a 2007 and I had put a J Costa variator on it. The J Costa gave great accelleration, but I took a pretty big hit in miles per gallon of gas, so I am trying a different route to improved accelleration. With the J Costa when I was travelling an indicated speed of 60 mph my engine rpms were approximately 5100. With my new bike I have installed 26 gram Dr. Pulley sliders and now when travelling at an indicated speed of 60 mph my engine rpms are at 4500. I will post more information as I take more readings on rpms vs speed. However, I have noticed that with the Dr Pulley sliders, the engine rpms are significantly lower at a given speed than they were with the J Costa. With the Sliders, the bike is not quite as quick as it was with the J Costa, but I definiatly like the better gas mileage. So far I have averaged from 52mpg to nearly 59 mpg, over the first 2000 miles on my new bike,

I think you can make easily a chart for your own scooter.

Put scooter on main stand and start engine.

Throttle to 20,30,40..mph and write down the rpm's .


The diameter of the drive pulley (front) is determinated by the rpm's of the engine.
The sliders don't see load, only rpm's.
You will be pretty close.
Althoug the real rear tire diameter will be less by the weight of the bike.
But not that much if pressure in tire is OK.


It's not a laboratorium methode.
Because rpm and speed gauges are not that accurate.

But you will have a good idea of the relation between rpm's and speed
OF YOUR scooter.
Stock parts ore not..., belt worn or not..no matter.

Eddy.