Chinese Engine Surging and Running Rough

[bob]

I have a chinese clone engine on a wood splitter. It is a 6.5HP horz shaft from Princess Auto here in Canada. Probably equivalent to a Honda GX200 or Powerease 212cc. My problem is it just surges up and down. I thought it was a carb problem but swapped carb and no better. Tried different sparkplug. Tried a different fuel tank and fuel line to eliminate fuel filter in gas tank. No difference. The one way I can smooth it out is by holding my hand lightly over the carb intake but I do not know what this means. I am cutting down the air flow ? It makes no difference if I have air filter on or off. It seems to have lots of power it is just irritating that it surges up and down

[KE4AVB]

It means that carbs needs rejetting as you have a very lean mixture and by holding your hand over the intake you are basically adding a choke condition.

Would need the engine actual model and spec info to look it up if possible.