For the first time, I adjusted the valves on my Huasheng 142F 49cc 4-stroke. All of the information I can find leads me to believe that the proper settings for this little engine are: .003" intake, .004" exhaust.
I've done a great many valve adjustments over the years (and all kinds of other work) on small- and large-block hot-rodded Chevy engines, so this was a pretty basic task for me. But, I was totally clueless as to which valve was the intake, and which was the exhaust!
In the attached photo (looking at the engine from the left side of the bike), you can see the two valves. I decided that the left side valve (closest to the exhaust) was the exhaust valve, and that the right side valve (closest to the carburetor) was the intake valve.
I made the two valve adjustments with my feeler gauge, after removing the spark plug and pulling the starter cord until the top of the piston was at its highest point in the cyclinder. Then I retightened everything.
I replaced the valve cover, put the spark plug back in place, and drank a cold beer. Then I pulled the starter cord, and the engine fired up on that one pull. It idled as smoothly as I've ever heard it: I've got the idle set as low as possible, and it just happily rumbled with a very even tone. Previously, this engine would idle with a fair amount of variation in its RPMs. This time, it was dead-steady.
But, when I took a test ride, I noticed a definite reduction in power. For example, pulling up a hill that never required pedal-help, I definitely needed to pedal.
Any thoughts, anybody? Did I mix up the exhaust and intake valves? Wrong clearances?
Thanks....
Max-M
I've done a great many valve adjustments over the years (and all kinds of other work) on small- and large-block hot-rodded Chevy engines, so this was a pretty basic task for me. But, I was totally clueless as to which valve was the intake, and which was the exhaust!
In the attached photo (looking at the engine from the left side of the bike), you can see the two valves. I decided that the left side valve (closest to the exhaust) was the exhaust valve, and that the right side valve (closest to the carburetor) was the intake valve.
I made the two valve adjustments with my feeler gauge, after removing the spark plug and pulling the starter cord until the top of the piston was at its highest point in the cyclinder. Then I retightened everything.
I replaced the valve cover, put the spark plug back in place, and drank a cold beer. Then I pulled the starter cord, and the engine fired up on that one pull. It idled as smoothly as I've ever heard it: I've got the idle set as low as possible, and it just happily rumbled with a very even tone. Previously, this engine would idle with a fair amount of variation in its RPMs. This time, it was dead-steady.
But, when I took a test ride, I noticed a definite reduction in power. For example, pulling up a hill that never required pedal-help, I definitely needed to pedal.
Any thoughts, anybody? Did I mix up the exhaust and intake valves? Wrong clearances?
Thanks....
Max-M
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