I recently acquired a 49cc china engine kit and figured it would be something good to keep my mind occupied during the winter. So I got it put together on an old panasonic bike from the 70s that doesn't weigh much and want to know what mods are worth doing to get it moving a bit quicker. Internal mods & bolt ons. Im new to this forum but theres talk about a "speed carburetor" the carb on it says speed and also has chinese writing on the choke, is this the 'better one' or do they all say that.