How is it supposed to feel at high speeds?

[hypophthalmus]

When I take my People 250 at high speeds, it feels kind of shaky, like I'm being oscillated side to side, and perhaps like my handlebars are oscillating a bit. This is at around 60-75mph on what I believe to be chip seal.

Is this normal? Is there anything I might want to check?

[zombie]

Of course the obvious... Steering head assemble, fork braces, wheel bearings. Lock up the front brake, and try to force movement in anything up there
 
Tire brand, and condition play a HUGE role. Perhaps you are just under inflated.

The scooter should NEVER feel "shaky or "squirley. I would not suggest trying those speeds till you sort it out.
If the bike begins to oscillate you are going for a very different type of ride.

[hypophthalmus]

I'm not sure what to check with the steering head and fork braces. I did what the manual said with turning the steering and compressing the shocks, but I didn't notice anything odd. I don't notice any play in the wheels either. The rear wheel was 1 psi overinflated, the front 1 psi underinflated.

I have noticed that with the rear wheel, it'll be easy to turn, then a bit stiffer, then easy again. It's apparent when the bike is idling on the center stand too, the wheel will vary in speed. Could this be involved?

For some reason the previous owner also replaced the front wheel only and with a different brand. The difference in wear is very apparent. Could that cause this?

[hypophthalmus]

I'm not certain, but it seems like the front tire might have been mounted backwards as well.  O_o

[BettinANDlosing]

It should feel good with your hands on the bats, but the people 250 and s250 have a very bad issue with speed wobble. Even new ones I've rode if you let go and coast no hands wobble violently after just a second or so no hands. They actually had a recall of the bar ends to put larger ones on (didn't fix the issue tho). Feel the tire surface with your hand for "cupping", that's where the tread is not smooth any more. And make sure your tires are set right 35/30psi. Is there any signs the bike has been in a crash? Bent lever scratched plastics etc. Or have you owned the bike since new.

[BettinANDlosing]

Oh Ps your front you're should look "backwards". It's actually the correct direction to sheer rain properly. Look for arrows on the sidewall that way "front rotation" or something of the like.

[hypophthalmus]

As I said, it's within 1psi of what it should be, although what you said is 5 psi too high. No sign of a crash, and the former owner said he never did.

It's unclear if what I was looking at was an arrow, because it'd be a slightly odd looking one. But I did find a picture with the tires mounted opposite of mine. I wouldn't think that'd make a different, but perhaps I shouldn't be too confident in whoever balanced them.

[BettinANDlosing]

If it was a balance issue it would be more like a pulse feeling up down bounce. The recommended tire pressure on almost all Kymcos is low unless you weigh less than 150. That bike should be pretty stake at 70-80 indicated mph. How long are your bar ends? Maybe it has the old style, the updated ones are almost two inches long.

[zombie]

No one caught what he said... The rear wheel is slowing at a point in the rotation... It's a bent rear out put shaft.

You will see a divot in the center of the rear shaft. With the bike on the center stand make some sort of rig to hold a pencil or a nail or whatever pointy thing you can find. Put the point into the little divot, and spin the wheel. If the pionty thing tries to move the shaft is bent, and AT SPEED THAT WILL TOSS THE BIKE AROUND.

[hypophthalmus]

Is that what the manual refers to as the final shaft? I don't see any exposed part to hold a pointy thing against. Unless you mean hold in it that gap to left of the wheel?

Could it be a loose nut or some such thing?

[BettinANDlosing]

He means the actual axle shaft aka output shaft. The circle is behind the muffler to the RIGHT of the wheel.

[hypophthalmus]

Oh, so perpendicular to the wheel? I stuck in a bamboo skewer and it seemed to be trying to move not at all.

[hypophthalmus]

I meant to comment on the bar ends as well. Do you mean the chrome ends of the handlebars? If so, they're a bit short of 2.5 inches long.

[BettinANDlosing]

Measure those bar ends I'll get back to you

[TLRam1]

I don't have any good suggestions, what year is your scooter? I have a 2010 People S 250 and it is smooth all the way up.

Good suggestions above, especially the axle. So many reasons, process of elimination or confining this to the front or back end.

Out of round tire, tire separation, bubble on the tire, balancing of the wheel, warped rotors, bearings in the wheels.