HuaSheng 142f to 144f upgrade questions

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#1
I'm looking to upgrade from my HuaSheng 142f to either the 144f or just go to the 79cc predator. I have all the parts for the HuaSheng including lots of aftermarket parts that I couldn't use with the predator.

My questions are; with exception of the piston size, is there any difference in sizing between the 142f and the 144f (will my exhaust from the 142 and other parts on the 144 indeed fit?) and what motor would you choose and why?
 


KCvale

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#2
My questions are; with exception of the piston size, is there any difference in sizing between the 142f and the 144f (will my exhaust from the 142 and other parts on the 144 indeed fit?) and what motor would you choose and why?
Yes.
I doubt you will be able to find a HS 144 engine though.
 
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#3
Yes.
I doubt you will be able to find a HS 144 engine though.

Excellent. Thanks for your help again, brother. I was lucky enough to track a new one down from a gentleman on here actually. I'm pretty excited. Hopefully I'll get an extra 1mph more out of her lol.
 

CrazyDan

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#4
The only way to gain additional overall mph going from the 49cc to the 53cc would be to have a lower gear ratio or ungoverning the engine. Just swapping out the engine you'll notice increased torque but no speed change other than a higher speed running uphill than before.
 
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#5
The only way to gain additional overall mph going from the 49cc to the 53cc would be to have a lower gear ratio or ungoverning the engine. Just swapping out the engine you'll notice increased torque but no speed change other than a higher speed running uphill than before.
do you know how to ungovern the engine?
 

CrazyDan

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#6
You gotta get a flywheel and magneto from an older hs 142f before they were electronically governed and swap them to your current hs 142f or 144f. Ungoverning my engine brought my top speed up from 27 mph to 35 mph on the same gear ratio. Not advisable to run at high rpms much, connecting rod will snap. I've searched everywhere for a billet connecting rod, looks like if I want my engine to last I'd need a machine shop to make one...I can't help myself...
 

darwin

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#7
Dan how are they regulated electronically? The pickup coil is a simple animal and doesn't look like there's any circuits in it. Billet connecting rod, is that a special rod? On fleabay they sell the rods, crankshafts for the 142f. Is yours' different?
 

CrazyDan

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#8
Dan how are they regulated electronically? The pickup coil is a simple animal and doesn't look like there's any circuits in it. Billet connecting rod, is that a special rod? On fleabay they sell the rods, crankshafts for the 142f. Is yours' different?
I know for certain there is no mechanical governor. I swapped over just the magneto just to try it out, it started right up but instantly died when any throttle was given. the older flywheel is timed 20 degrees off from the newer ones. A billet con-rod would be one machined from a block and not drop forged, normally this would be a mod done if rpms are increased. the stock rod can't handle screaming above 8k rpm long, awaiting mine to asplode.
 
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#9
dan is correct, it is in the ignition. Im wondering though, since the honda gxh50 is basically the same engine with no rpm limit, if ordering a replacement flywheel and CDI for that engine, would work...? any thoughts?
 
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#13
It all depends on timing from the flywheel.
must be different. i ordered a replacement cdi for the honda engine (granted, it was only a $10 from china on ebay) and the engine had no power. it started and idled, but would not push the bike with me on it.

that being said, if i changed out the flywheel, with one for a honda ghx50, you think that help solve the issue?
 
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darwin

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#14
The honda gxh 50cc pickup coil will not interchange and work with the HS 142f. I know from swapping them out and testing them. They look alike but there's a subtle difference in the way they mount. It puts the timing off just enough not to work correctly is my theory.
 
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#15
so do you think a honda cdi/flywheel combination would work?

also, maybe im looking in to your post above too much, but have you actually cut in to and opened up one of these limited CDIs? If so, im curious what you saw.... (as that is what im about to do...) lol
 
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darwin

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#16
It's just a pickup coil, no electronics in it. You can tell that by just looking at it. I've never cut into one. I do know the older HS 142f's were faster than these newer ones. Exactly when is a good guess, maybe when they were EPA approved.
 

CrazyDan

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#17
It's just a pickup coil, no electronics in it. You can tell that by just looking at it. I've never cut into one. I do know the older HS 142f's were faster than these newer ones. Exactly when is a good guess, maybe when they were EPA approved.
Its not quite like you think, I have an older flywheel/ magneto combo that cannot interchange at all. The pickup is at the exact same spot with both. No mix/match can make it work right unless its the matched parts. The magneto fires the spark at a different time from old to new, even if using the same flywheel. Something magical is happening in the magneto.
 

darwin

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#18
I could swear back in 08 I had a 142F FD setup with 1-1/8th roller and I could go 30mph. With these newer ones I top out at 22mph with the exact same setup.
 

CrazyDan

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#19
I could swear back in 08 I had a 142F FD setup with 1-1/8th roller and I could go 30mph. With these newer ones I top out at 22mph with the exact same setup.
That would be ungoverned vs governed. If you still have the old engine scavenge the flywheel and magneto to get 30 mph back
 
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#20
well guys, i just did it!!!! After taking the CDI and flywheel off of the huasheng, and replacing them with replacement parts for a honda gxh50, i was able to remove the RPM limiter. Im unable to ride it for a few days, but after lifting the back tire off of the ground in my garage, and holding the throttle wide open several times before, i got a feel for what it sounds like completely maxed out. After making the switch tonight, and performing the same test, that engine made sounds ive never heard from it before! It revved up higher than any weed eater ive ever heard, i honestly believe if i would have held that throttle i would have blown the engine. Vibrated like ive never felt before, too haha.

anyways, i hope this information helps someone in the future..

The part number for the Honda CDI is 30500-ZM7-014
and the flywheel is 31110-ZM7-004

I just searched ebay for both of those numbers and got the CDI for less than 10 shipped, and the flywheel was $30 shipped.
 
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