Hmmmm the weedwhacker has potential. As I understand, a generator is simply a gas engine hooked up to an electric motor (simplified). The weedwhacker engine is about 10 pounds. If I connect it to an r/c electric motor (same model as I will be using to power my ebike) the total weight would be about 17 pounds. I am guessing that the weedwhacker will work well at about 7,500 rmps, which is about 3,000 more than the motor on my bike will be turning. How long can I expect the weedwhacker to last if run in a constant speed mode with good filtered fuel and a synthetic oil? 500 hours? 1000 hours? Is this something that could be rebuilt - new piston, rings, bearings, etc or is it something that CANNOT be rebuilt? Please note - I am not consider the cost of rebuilding or replacing. I hope to make my ebike a land yacht and cruise through parts of China that would probably not have a 35cc gas engine available, so rebuilding would be the most convenient option if it started to lag. Would a Honda weedwhacker motor be more reliable? Can I get a better carburetor for this or other things to improve the performance and reliability? What if I want to go up a step and get a 35-50cc engine with a starter? Still, if the weedwhacker is connected to an electric motor to generate electricity, I can use the electric motor in "motor mode" to work as a starter for the weedwhacker engine. Lots of questions here
I hope to implement this in the summer but I have to make some decisions now about how to use the space on my ebike. I want to buy the lithium batteries now - at US$ 400 an expensive proposition - and i won't be able to change my decision after I make it. The batteries come in a variety of shapes.
Here is a pic of a bike like me, just so that you know what I am beating one
http://item.taobao.com/item.htm?id=9945325151