What could reduce top speed?

[ClayMation]

Hey Guys,

So I have noticed a top speed decrease from about 97ish MPH to now getting up to only about 90ish.

After my 4k service the service guy didn't mention anything about anything looking or sounding off kilter about the bike so i'm not sure if this is a normal speed reduction or not.

My observations are as follows, the first 2-3 months I had the bike my top speed was about 97 MPH maximum, but in the past month and a half I have noticed a decrease in this speed to about 90 or so.

Maybe it's just taking longer for the CVT to find the cycle (in other words, I would have to be fully throttled up for a minute to get to 97) but in the first 2-3 months it was getting there within 10 seconds when fully throttle up.

Mind you, I do not test for top speed often, just in situations where it is absolutely necessary, such as being tail gated by a SUV doing 85 behind me.

So, what are some things that can reduce top speed by around 5 mph?

[Stig / Major Tom]

Belt wear...when width of belt wears scooter will lose a few mph off of top speed.

Stig

[AMAC1680]

Any recent valve adjustment ?
Out of wack valves will also drop top end.

AMAC

[ClayMation]

Belt wear...when width of belt wears scooter will lose a few mph off of top speed.

Stig

Interesting, they said the Belt looked really good during the inspection with plenty of life left.

[ClayMation]

Any recent valve adjustment ?
Out of wack valves will also drop top end.

AMAC

No valve adjustments yet since purchased out of the factory. At what mileage is a valve adjustment suppose to be done?

[Mr. Paul]

Interesting, they said the Belt looked really good during the inspection with plenty of life left.

Heres some possible causes. I would eliminate them to find the cause.

1. Tire pressure

2. Different driving situation; Headwind? Slight uphill? Curves? Ambient temperature?

3. Belt wear. (Measured with a caliper)

4. Any flat spots on the rollers?

5. Air filter?

6. Spark plugs?

7. All you can eat buffet at the Chinese restaurant? 

[ClayMation]

Heres some possible causes. I would eliminate them to find the cause.

1. Tire pressure

2. Different driving situation; Headwind? Slight uphill? Curves? Ambient temperature?

3. Belt wear. (Measured with a caliper)

4. Any flat spots on the rollers?

5. Air filter?

6. Spark plugs?

7. All you can eat buffet at the Chinese restaurant? 

Been monitoring tire pressure 3 times a week.

The wind has been picking up a bit lately, as Southern California transitions into winter.

The belt was examined during my 5k Service two weeks ago and they said it looked great.

Flat spots on rollers has not been checked into. Causes for this?

Air filter was changed out at the 5k service.

Spark plugs is a thought.

On that last one, I actually had an all you can eat Korean BBQ recently and I still only weigh in at 160 LBS.

[Tromper]

Winter blend gas?
It is that time of year.  I've noticed my biannual MPG change relating to that.
Never noted a drop in power since I rarely run the SYM on the freeway (tops a bit over 70), & it takes a track or a lot of space to get the burger to top out (110+), but there probably is one to match the MPG.

[Stig / Major Tom]

Looking at a belt is rather different than measuring the belt width. When the width wears away the top speed is reduced. Can be a fine looking belt with a few mm's worn away along the edges....and you will slow down.
Would take a very special mechanic to eye-ball a missing mm or two of a belt's width.
+I'm thinking if you need more than 90mph....you need to get two more wheels under yourself.

Stig

[gwdoiron]

+I'm thinking if you need more than 90mph....you need to get two more wheels under yourself.

Stig

Actually, they have these things called racetracks that you should use, if you want to run at those speeds.

Keeps you from killing other people on the road.