50cc upgrade

[glandin]

Bought a 80cc upgrade for my 50cc gy6. Installed it and was able to get a whopping 17 mph out of it. According to the instructions that came with it, no additional adjustments or additions were necessary. My mechanic redid it overhaul and managed 17 mph. What do I need to do?

[harry]

17mph is the maximum speed you can go???
try a valve adjustment....

oilyhans

[glandin]

Will try valve adjustment when I get home in September.

[glandin]

What size main jet do I need to install when I upgrade from 50cc to 80cc? Tried the valve adjustment to no avail.

[harry]

try about a 75 mj to start with ,but buy a couple or 3 so you
can test run your scooter and find the right one.

oilyhans

[Sylaous]

Don't forget..if you rejet your carb, to be certain your Air intake and exhaust are upgraded as well.