Here is my professional opinion as a motorized bicycle builder and vendor of bike engines.
There are a lot of good 4 stroke engines out there that will drive you for upwards of 50,000 miles without any major hassles. Shoot, we are creating our own 4-stroke design...
But, it is very important to know that the 4 stroke bike engines that are of any value are going to cost at least $500.
Out of China there are 2 cheap 4-stoke kits, the Starfire Gen 2 and another no name that also fits the Honda GXH50 and its Chinese replacement the Hua-Sheng 49cc. The quality of workmanship that goes into the inexpensive 4 stroke gearbox is SO BAD that I receive many emails asking us for replacement service parts. I hear of bushings prematurely wearing after 10 hours of riding and woodruff keys shearing. The Starfire is better than the no name but many problems still arise from poor quality control. The engines are nice, strong engines. They are not the best on the market because of their aluminum cylinder and chrome bore, but they work just fine and fire up every time. It is how the gearboxes are made that is so troubling.
If you are interested in the no name engine that is pictured below, please reconsider. This engine gearbox is the cheapest piece of junk I have ever seen on the planet. The ebay seller who sells this does not offer a warranty and will not honor refunds or exchanges to fix the problems that occur. We purchased 5 of the engines and each of them quit after 8 hours of use. We lost thousands of dollars in testing this product with no recourse to fix the problems. My Chinese contacts do not have replacement parts either. The centrifugal clutch bell housing cracked in half and woodruff keys sheared. Why? Because on close examination, there is not a single straight line or cog inside the engine.
Thank you for letting me rant.
Cheers. Roland
Post edited by: spookyto, at: 2008/07/13 01:05
