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First shop or second shop?


Matt

The difference. The price itself seems pretty in line with what I've seen around the country.


Matt

Ahh, well, not normally, unless they are really seized on there. Then I guess it could be an issue. Really, just go get an electric impact gun at Home Depot. It's about the most useful tool you can own anyway, and it makes short work out of stuck case bolts. (And drywall screws... wood screws... any screws and bolts you happen to come across.)

Or you can use one of these: www.partsforscooters.com/202-34-Pit-Posse-Impact-Driver
Once you figure them out, these little guys work like a charm as well. I've had one in my toolbox since my first restoration 10 or so years ago and I still use it on occasion. If you hit them just right, you can get some really really stuck bolts unstuck pretty quick (or at least shear off the head trying).


Matt

The bummer on this one is you are probably going to have to open that up before you can be 100% certain of what you need.


Matt

Couple of things here:

First off, a GY6 longcase will support up to a 13" rim, there isn't clearance for anything larger. The "B" cases are designed to support up to a 16" rim, but that is a whole different engine, and therefore probably not applicable. When you are looking at tires, the first number is the width of the tire in millimeters mounted, the second number (this is the money number for a taller tire) is the height of the sidewall as a percentage of the width of the tire, and the third number is the diameter of the rim.

So for example, a 100/60-12 tire, would be 100mm wide mounted, with a 60mm tall sidewall and fit on a 12" rim while a 130/60-13 is a 130mm wide tire with a 78mm tall sidewall that fits on a 13" rim. The tallest tire that fits on a standard 157QMJ and is readily available is the 140/60-13, which features an 84mm sidewall. This increase in overall diameter is incremental however and probably not worth the added weight of the taller tire (which I'll get to below, there is a usually a solid 1.5-2 lb difference from the 130 to the 140).

Looking for -16 or -17 tire options won't help unless you plan on changing out your whole engine unfortunately. This being said there are many 16, and 17" tires are a very common motorcycle size as well. Normally all of these tires tend to have higher sidewalls however.

Now with that out of the way, in theory, a taller rear can in fact give the potential of a higher top speed, but there are some other factors that come into play here that limit what can be done, and they all factor in the limited power of the GY6 engine. Since the GY6 just isn't really all that powerful, it is pretty sensitive to increases in rotating mass on the rear wheel, not to mention that you'd probably be looking at additional transmission tuning.

Also, it's simply harder for the GY6 to propel a scooter through the air at sustained higher speeds without something that helps the bike to make more power, such as a BBK or other power adding options. This also applies to changing out the gears for a better top end ratio. You might see a bit of an increase, but the GY6 can't make the most of that kind of modification at it's stock power levels.

Nerd alert, but here is the why on the aerodynamics thing, because even at the lower speeds of scooters, it is a very real factor. As many of us know, getting into a tuck really does add a few MPH on top. Anyway, here goes: Aerodynamic drag increases at roughly the square of speed. That is, while power increases in a linear fashion, drag increases exponentially with speed, in a parabolic function. For example, if 100 horsepower would push a certain vehicle 100 miles per hour through the air, doubling the speed to 200 would require two-squared or 400 horsepower to overcome air resistance, while 300 miles per hour would require 900 horsepower. A simple reduction in frontal area reduces the amount of drag, hence tucking.

In short, it's a great engine and a lot of fun to play with because it is relatively simple, but a powerhouse she is not in stock form, and that is the biggest limiting factor for the top speed of the GY6 overall.


Matt

Credit to these guys for the aerodynamic formula used here.

The Elite 80 is just one of those bikes where you are better off accepting it for what it is, a reliable not all that fast bike. If you want to go faster you are better off looking at a bigger bike.

The only thing you can really do for the CH80 is air in, air out and some transmission tuning... It's pretty limited unfortunately.


Matt