MOPED ARMY

You own 4 mopeds and still don't know what a jet does? Do any of them run?

naw theres a lot more to it than that.

Hi Jim, to answer your questions, there are many factors that determine how fast a mopeds goes. When these bikes were sold new there were usually three speed levels available. 17mph, 25, and 30mph bikes. What made them different was a variety of factors. These included the size of carburetor installed, the jet (which only controls how much fuel gets mixed with the incoming air) the compression, the timing, the gear ratio, etc.

One of the most common performance enhancements for these bikes is to put a high flow air filter on the bike. Now, since they are carbure-ted, there isn't a computer to keep track of how much air is coming in and adjust the fuel mixture accordingly. So if you supply the engine with more air, you have to put in a larger jet as well so that the fuel/air mixture remains stable. If you run with too much air and not enough fuel, you risk overheating the engine and seizing it. If you run with too much fuel and not enough air you will have poor performance, and are likely to foul spark plugs with all the soot that will be formed.

Quite often though, you can take a 17mph bike, or a 25mph bike and make it perform much faster than it was originally designed to. For example, I have a Puch that was the 17mph version originally. It now runs 32mph, so don't be discouraged by a low speed bike unless you don't plan on tuning it yourself.