Hi all, I am new so here are some things about me. I have a Rotary brand bike,it has a 30cc 2 stroke motor built into the rear wheel. It is a close copy of the Sachs 30cc. It is a neat setup but it is a rope pull to start,this is bad but it is the only drawback of this model that I can see. I can wind it out to about 40kph,and that is fast enough for me on a bicycle. I live in a small town where so far I have only spotted 2 other powered bikes,they passed and waved but could not stop to talk. Anyhow I have a Question, What could cause the petrol mix not to flow when I have a filter in the fuel line?,take the filter out and it runs fine,put it in and fuel problems result.Any help appreciated!