Re: Bicycle Enjenn
I didn't have to do anything to mine. These engines aren't like the 2-strokes where you have to go through them to get em somewhat reliable. The valve adjustment may be way off tho, so it's a good idea to do a valve adjustment before you start the engine, and then another one down the line. It is possible that you may get a defective carburetor. The carbs are very sensitive, you need a good fuel filter. Mine worked for ~100 miles and then never worked right again. I had to replace the carb.
Other than keeping the valves adjusted and occasionally changing the oil, there's usually nothing that needs to be done to these Huashengs. You don't even have to adjust the valves, you just get the most power out of the engine when they are adjusted properly.