upgrade 49.5 cc to 70cc

[hieumait]

Does worth to upgrade my 2003 super 9 49.5cc LC to 70 cc Cylinder Piston Kit Kymco Super 9 LC Dink 50 cc (Airsal 47.6mm Big Bore 70cc Cylinder and Piston Kit ), thank

[chaz35]

I wouldn't do it until I figured out how to make 49cc run.

Your 49cc should be very fast with 125# rider, if it's tuned right.  You said it had tuned pipe, so just needs some TLC, and may surprise you how fast it can be.  Speedo arm, on my Super 9 LC, goes past the bottom right hand corner of the mileage box from time to time, I think going over 55mph, its turning over 10,000 revs and sounds sweet.

Or, maybe 70cc kit would be the easiest thing to do?  You have LC so should run cool.  Only 70cc kit I did was AC, I had trouble getting it to  run cool, so I wouldn't do 70cc kit on AC engine again, but will probably do 70cc on LC.  Unless you get taller final gear, 70cc doesn't make for more top speed, but a lot more torque, and acceleration.  Cheers

[paceneedsstides]

yeah I would definitely figure out why you're not running right first then do BBK aka Big Bore Kit also as a beginner DO NOT DO ALUMINUM KIT get a cast iron kit as they are more forgiving and last longer then single ring aluminums are more for racing applications and people who don't mind tearing into it to replace rings and or piston more often.

[hieumait]

thank you for the in put, does anyone know where i can get tune jet for carb or how tune carb?

[chaz35]

hieumait, if you have some time, do some reading on this forum, it's all here, where to buy jets, how to tune carb, CVT, install BBK.  You will find conflicting information, so you will have to decide what seems best for you, just like the rest of the web.  I had a lot of fun researching, then tweaking my scooter, getting it to run better.  Hopefully, you will have a similar experience.

Have you checked your carb jets?  With the OEM carb, you can change idle jet and main jet.  Is your new carb still OEM carb?

[hieumait]

new carb it oem, in service manual oem Main jet(Unlimited/limited speed)#92/#78, I wonder if i can go little bigger like #95 or #96 by drilling it out?

[paceneedsstides]

I wouldn't drill out jet as you might go to far and then not have a replacement just buy an assortment of jets they're only a couple bucks each