Hello fellas,
After lot of research I successfully ungoverned my HS 142. The thing is, its a lot easier than you think.
There are lot of HS engine models, such as old models from around 2010 which they have no rpm limit whatsoever, then newer models (probably from 2013 to 2019 idk I'm just guessing) which they have rpm limit in flywheel and ignition coil (to max 6800 rpm) if you wanted to ungovern this thing you needed to replace both things, which could be costly. Because the difference between new and old HS flywheel is, the keyway are +- 20% degrees offset from each other.
And the thing is you need to have same keyway position on your flywheel like on Honda GXH50 (which is basically the same engine but with no electronic rpm limit)
Luckily if you own a new HuaSheng model, you probably have a basically same flywheel like from Honda (with some minor detail on magnet surface)
So how do you ungovern newer HuaSheng 142F engine? Just buy the original Honda's GHX50 ignition coil and you are good to go. Well, easy to say but its little tricky. For example on aliexpress there are lot of "original" Honda GHX50 coils but there are not, they are from HS and because they fits on Honda they call it "Honda GHX50 Ignition coil" just a Chinese thing.
So there is a link on aliexpress where I bought that ignition coil like 2 months ago and I'm telling you that it unlocked my rpm to, basically unlimited. When I have rear wheel in the air I got 10K+ rpm. Of course this is rpm's without any load.
After installing Honda's coil, tbh I didn't experience any significant speed boost. Maybe because when I'm riding my motorized bike my rpm's are below 7k anyway because the engine can't sustain that high rpms. Maybe because I have high gear ratio idk. I have 26'' wheels, a CVT transmission which has gear ratio 3:1 then in CVT there are another gears which basically reverse my rotation on shaft from CW to CCW (52T to 14T) And then I have 8 teeth gear on output of transmission and 44 tooth sprocket on rear wheel but I still got top speed around 50 kmh (31 mph) which is fine for me.
And another important thing to mention is, if you own a HuaSheng engine you probably have aluminum connecting rod, that rod is fine but if you really want to give a hard time to that engine I recommend buying a forged rod, I believe is the same rod like, again, on Honda GXH50 but I'm not sure. It has a both bearings on crankshaft and on piston which is always a plus.
So this is it. I hope I helped a little.
After lot of research I successfully ungoverned my HS 142. The thing is, its a lot easier than you think.
There are lot of HS engine models, such as old models from around 2010 which they have no rpm limit whatsoever, then newer models (probably from 2013 to 2019 idk I'm just guessing) which they have rpm limit in flywheel and ignition coil (to max 6800 rpm) if you wanted to ungovern this thing you needed to replace both things, which could be costly. Because the difference between new and old HS flywheel is, the keyway are +- 20% degrees offset from each other.
And the thing is you need to have same keyway position on your flywheel like on Honda GXH50 (which is basically the same engine but with no electronic rpm limit)
Luckily if you own a new HuaSheng model, you probably have a basically same flywheel like from Honda (with some minor detail on magnet surface)
So how do you ungovern newer HuaSheng 142F engine? Just buy the original Honda's GHX50 ignition coil and you are good to go. Well, easy to say but its little tricky. For example on aliexpress there are lot of "original" Honda GHX50 coils but there are not, they are from HS and because they fits on Honda they call it "Honda GHX50 Ignition coil" just a Chinese thing.
So there is a link on aliexpress where I bought that ignition coil like 2 months ago and I'm telling you that it unlocked my rpm to, basically unlimited. When I have rear wheel in the air I got 10K+ rpm. Of course this is rpm's without any load.
After installing Honda's coil, tbh I didn't experience any significant speed boost. Maybe because when I'm riding my motorized bike my rpm's are below 7k anyway because the engine can't sustain that high rpms. Maybe because I have high gear ratio idk. I have 26'' wheels, a CVT transmission which has gear ratio 3:1 then in CVT there are another gears which basically reverse my rotation on shaft from CW to CCW (52T to 14T) And then I have 8 teeth gear on output of transmission and 44 tooth sprocket on rear wheel but I still got top speed around 50 kmh (31 mph) which is fine for me.
And another important thing to mention is, if you own a HuaSheng engine you probably have aluminum connecting rod, that rod is fine but if you really want to give a hard time to that engine I recommend buying a forged rod, I believe is the same rod like, again, on Honda GXH50 but I'm not sure. It has a both bearings on crankshaft and on piston which is always a plus.
So this is it. I hope I helped a little.