How to really ungovern HuaSheng 142F (2022)

Elding

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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 motor 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 (but don't know the gear ratio of that thing) 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.
The cold start up is for some reason a worse than on HS coil. It takes lot of pulls until engine finally starts up.

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.
 

Sidewinder Jerry

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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 motor 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 (but don't know the gear ratio of that thing) 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.
The cold start up is for some reason a worse than on HS coil. It takes lot of pulls until engine finally starts up.

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 cast iron 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.
According to your information, your lowest reduction is 16.5\1. It'd take a minimum of 6613 rpm with your setup to do 31 mph.

If your cvt has a reduction range of 6\1 to 3\1 then you have a total reduction range of 33\1 to 16.5\1. The 33\1 is around the lowest bottom range your engine can handle for a level ground take-off ratio. My level ground take-off reduction is around 37\1. If your total weight is over 300 lbs around a 10% grade hill climb is the most your bottom-end reduction range can handle. If your total weight is 220 lbs or less you may be able to climb a 15% grade hill with a lot of pedal assist
 

michael whiteman

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If you trade the aluminum connecting rod for a steel one that will definitely screw up the balance.
And why would you want to put a heavier component in your engine?
 

zean

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That's a good point about the balance factor of the crank. If a person exceeds the 6800rpm limit of the HS142 they want a steel connecting rod because: 1). steel is stronger than aluminum and 2). the longer you use aluminum, the weaker it gets. Steel has an exact breaking point, if you exceed that limit the steel will break. Aluminum is strong. After prolonged use, a small amount of force can cause aluminum to fail. Aluminum has been the unknown source of many airplane crashes.
 

Elding

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If you trade the aluminum connecting rod for a steel one that will definitely screw up the balance.
And why would you want to put a heavier component in your engine?
Yeah well, if you wanna swap to forged rod you will swap your crankshaft anyway because I believe you cant buy forged rod alone. At least I bought them together, crankshaft and con rod and I can say they are better quality than the stock one. I swap them after like 1400 km (870 miles) and the crankshaft bearings were little loose on the stock one. And the GHX 50 crankshaft has better balance. So you are right about the balance but if you swap both crankshaft and rod it shouldn't be a problem.
The both rods are about the same weight. The aluminum rod is light but thick and the forged one is slim but steel is heavier but the difference is like few grams. So no worries.
 

Elding

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According to your information, your lowest reduction is 16.5\1. It'd take a minimum of 6613 rpm with your setup to do 31 mph.

If your cvt has a reduction range of 6\1 to 3\1 then you have a total reduction range of 33\1 to 16.5\1. The 33\1 is around the lowest bottom range your engine can handle for a level ground take-off ratio. My level ground take-off reduction is around 37\1. If your total weight is over 300 lbs around a 10% grade hill climb is the most your bottom-end reduction range can handle. If your total weight is 220 lbs or less you may be able to climb a 15% grade hill with a lot of pedal assist
Thanks jerry, that's pretty accurate. I don't have much weight, I'm around 65 kg (145 lbs) So I think my engine is happy about it :D
 

DAMIEN1307

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Aluminum has been the unknown source of many airplane crashes.
If aluminum has caused airplane crashes and is KNOWN to suffer from metal fatigue over time and has caused some crashes if not replaced during normal safety checks. how can you say it is an "UNKNOWN source of many airplane crashes"???...lol...The statement does not make much sense...lol...Just saying...lol.

Airplane accidents are meticulously studied and everything is tested and inspected on a downed plane after a crash by NTSB or other countries equivalent thereof, even calling in the US NTSB for help when needed until they pinpoint what causes a crash...Therefore the causes of crashes IS KNOWN, in order to prevent it from happening again in future...lol...Many improvements and proceedures are changed and/or implemented in the aircraft industry because of these studies and tests and inquiries...lol.
 

Cannonball3

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The early Bonanzas shed the tail. They finally figured out it was due to the tail cone being flexed due to the material being under rated. A slight increase in the aluminum thickness solved the problem. Interesting story on how they figured it out but its too long to relate in this thread.

My take on the HS being unlimited is that its just asking for trouble. The fact that the little engine is as reliable as it is considering its origins makes me tend to want to baby it a bit. Its not a Honda. If it was it would be different. I run mine around its torque peak in the upper 4k range. It cruises nicely in 7th @30mph there. I can and have twisted it to max and its quicker, but it vibes more. The gearing on my build just by a stroke of luck is matched perfectly to the torque peak. Its a most pleasant little ride. We all are in the hobby for different reasons and have different builds for different ideas. I applaud experimentation! Make it go as fast as you can if thats what you want. Might be better to start with a GXH 50 however. Wish I had one!
 

Sidewinder Jerry

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A tachometer is a very good thing to get. On my 4-stroke RS 35, the max torque is 5000 rpm (1.2 ft/lbs), the max horsepower rpm is 7000 rpm (1.6 hp), the redline is above 8000 rpm and the recommended idle is 3000 rpm. The clutch engages at 4400 rpm. This is why I use a gear at full throttle that keeps me between 6000 to 7000 rpm. This range ensures the clutch is fully engaged.

My engine and clutch are over 12 years old with close to 5000 hours of use on it. At a 15 mph average speed, that is around 75,000 miles. Change the oil every 25 hours, check the valve lash clearance every oil change, clean the air filter every 10 hours, change the fuel filter every year, and only use 100% ethanol-free gas.

I also have a Honda GXH 50 that I plan to use one day. Its max torque is 4500 rpm, max hp is 7000 rpm, redline is over 7500 rpm, and recommend idle is 2800 rpm.

Your engine specs are very close to the Honda except you generate 1.6 hp at 6800 rpm and the Honda generates 2 hp at 7000 rpm. Your engine generates 1.2 ft/lbs of torque at 4500 rpm and the Honda generates 2 ft/lbs of torque at 4500 rpm.
 

Elding

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Your engine specs are very close to the Honda except you generate 1.6 hp at 6800 rpm and the Honda generates 2 hp at 7000 rpm. Your engine generates 1.2 ft/lbs of torque at 4500 rpm and the Honda generates 2 ft/lbs of torque at 4500 rpm.
What makes the Honda engine more powerful? The bore and stroke is the same isnt it Jerry?
 
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