50cc To 80cc CVT upgrade? By sooonmitch (Read 1,449 times)

[sooonmitch]

So I recently upgraded my engine (gy6 50cc) to a BBK of (80cc). Its great and all but I feel the power is useless unless I find and upgrade for my CVT trans. So here is my question, what kit can I get to upgrade my CVT trans? I have been searching around and I cant really find any. I want to get it so I can handle higher speeds at lower rpms than I am now. I do not plan on taking it on any high ways or interstates. I just want it to have a lower RPM while traveling 45 mph or so on side roads. Is their a certain kit I should get or should I upgrade something else or what? Thank you in advance.

[trashtruck12172]

I might be wrong but now that you have more power, (50-80cc) I'd start looking to upgrade final gearing if you're looking for more speed.

[sooonmitch]

That is what I want to do but I cant find a kit for it or even know where to start...

[trashtruck12172]

i guess the best starting place would be to open up the transmission and see exactly what's in there.

[sooonmitch]

Its contains the default CVT gearing that comes on a Chinese 50cc GY6 engine

[thecableguy]

Try this link for the gears.

And look thru this post to see how it's done.

Jim

[sooonmitch]

Is there anything that is less involving? I do not trust myself, doing all that to my bike... It is my only means of transportation..

[thecableguy]

Maybe my link to the procedure was misleading. You don't have to take the engine completely apart like in that post, just the CVT and rear gears. That was the only post I could find with pics and a description of having the gear "pressed" off and on to the shaft by a machine shop... That's the hardest part...

Take a look at the post again, I'm just talking about this short part:

Next we removed the final drive cover and the drive gears.

(SOME PICS HERE)

This pictures below shows the old gears and the new. The pilot shaft has to be pressed off the old gear and pressed on the new. You will need a press for this. Most local garages should have one and not charge but a couple bucks to do this. Do not attempt to use a torch and a vise to do this. You will damage the gear or shaft.

(COUPLE MORE PICS HERE)

Nov 13, 2014 12:26:09 GMT -6 Alleyoop said:

See the Reduction Gear on the shaft well that is pressed onto the shaft so you have to PRESS IT OFF

Because when you order taller gears you do not get the reduction gear you get the shaft and the findal drive gear. So you then have to take the reduction gear off the OLD SHAFT and press it onto the new taller geared shaft.
Hope I cleared up "the press it on press it off" confusion
Alleyoop



THIS IS WHAT YOU GET WHEN YOU ORDER TALLER GEARS:

[thecableguy]

Video by Scrappydog Scooters showing the procedure.

[vandan]

I may be doing the same thing, can I press the gears on and off with a three jaw puller? Or would that damage them?

[thecableguy]

No, you need to take it to a machine shop. They've got the proper hydraulic press to do it without damaging it.

[jjoshua20213]

You need to get an A9 camshaft and around 7g weights.