Big bore
 

Has anyone put a 50mm big bore on a taotao thunder with a gy6 I will be doing it in the next few days just looking for someone that has if I run into any problems:thanks:

Research resource . . enhanced odds of bearing failure.

If this style muffler. . only remove top ear bolt, then pivot on loose bottom ear bolt, after removing 2 bottom head exhaust pipe nuts. Suspend muffler from upper frame with a cord. During assembly, install top and bottom cooling shrouds prior to muffler attachment.

Jets and idle
 

I put in the 80 cc kit runs great but hard to get started and idle is bad and it is needing more gas I have put a cone filter on as well but still have stock muffler and suggestions

Pilot and main jet sizes?

If using the stock head which has around a 5cc combustion chamber . . .
39mm bore (50cc) = around 10:1 static compression ratio
44mm bore (63cc) = around 12.6 static compression ratio . . resource
47mm bore (72cc) = around 14.4:1 static compression ratio . . resource
50mm bore (81cc) = around 16.2:1 static compression ratio
52mm bore (88cc) = around 17.6:1 static compression ratio

For comparison . . .
Sym 50 11.8:1
Honda Ruckus 50 11.9:1
Yamaha Vino 50 12:1

Static Vs. Dynamic Compression Ratio

1 teaspoon (4.9 cc's) in a stock 139QMB cylinder head . . .

http://i.imgur.com/K3H7Dze.jpg

http://i.imgur.com/AC6VKpJ.jpg