Honda versus Huasheng w Belt Drive Trans

snelson203

New Member
Mar 20, 2014
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Philadelphia Area
TOTALLY new to this but want to build my first motorized bike. Picked up a nice Genesis Astra 7 speed bike at Walmart for $139 on sale. Solid AL bike with space for a 4 stroke. Read online that I should cut some conduit to use behind engine clamps during mounting to spread the load of the clamp and protect the AL- so that much i know.

Here are my questions:
I know the Honda engine is expensive(about +$250 from the Huasheng). Is it worth it? What are pros and cons of these two engines?

On transmissions- is the 4G T belt drive the best to use? Is this 80T w/ freewheel the preferred product?

What other things do I need to consider?

THANKS IN ADVANCE. I want to buy the correct parts and avoid the rookie mistakes.
 

The_Aleman

Active Member
Jul 31, 2008
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IMHO, the Honda GXH50 is not worth the price premium over the Huasheng. The Honda _is_ the better engine but over twice as good (price)? No.

Honda GHXH50 Pros:
It's a Honda and has Honda build quality!
Runs a little quieter, has slightly more power
Has a real 5/8" keyed shaft, works great with B-E's 4G or the EZM Q-Matic

Honda GXH50 Cons:
Costs twice as much or more compared to Huasheng
Has a governor and low oil switch - both should be disconnected
The carburetor isn't set up for our throttle, needs either a linkage kit or a carb swap
Real Honda replacement engine parts are not cheap should it need to be rebuilt

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Huasheng Pros:
Costs much less than a GXH50
Doesn't have a governor or low oil switch
The carburetor is already set up to take our throttle
Has almost the same power and reliability as the Honda (some here have logged over 10K miles and still going strong)
Replacement parts are very cheap should it need to be rebuilt

Huasheng Cons:
The carburetor can be finicky, may need cleaning or even replacement
The intake/exhaust valves may need to be adjusted more often than the Honda
Some newer Huashengs have sealed adjustment screw on carb, may need plug drilled out
The 5/8" shaft version isn't really 5/8" (needs a shim)

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Either way you go, the GXH50 and Huasheng are great little engines. They can run hard all day and have excellent long-term reliability
as long as they aren't overrevved too much. If you keep em under 8K RPM, they can run quite a long time before a rebuild is needed.

When considering what transmission to use, that's going to be up to you. The 2 most common are the 4G and the Q-Matic.

The 4G is cheaper, more compact, offers better off-the-line acceleration.
The Q-matic is more expensive, larger, offers better long-range cruising.
Do some forum searching to figure out which one you want.
 

snelson203

New Member
Mar 20, 2014
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Philadelphia Area
Aleman- I am a GA TECH engineer so I get some of the gearing stuff, but what is the difference in performance from the 4G with 80T/ 90T and 100T. I know 4:1/ 4.5:1 and 5:1, but what do you get as you go up? Better top end, better low end? THANKS
 

The_Aleman

Active Member
Jul 31, 2008
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el People's Republik de Kalifornistan
With the same rear sprocket, an engine with more reduction (higher numerical ratio) will have a lower gear. Simply put, better low end.

Examples:

4:1, 12T output, 48T wheel sprocket = 4 * 4 = 16:1 overall (~34MPH @ 7K RPM with 26" wheel)
5:1, 12T output, 48T wheel sprocket = 5 * 4 = 20:1 overall (~27MPH @ 7K RPM with 26" wheel)

16:1 overall is pretty much ideal for all-around performance with a single-speed setup.
A typical Huasheng has about enough power to attain ~36MPH on a flat without wind.
 

snelson203

New Member
Mar 20, 2014
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Philadelphia Area
Just got kit last Friday. Have made good progress on it. Taking my time and ran into a bit more grinding/ drilling and tapping than I anticipated to get the motor mounted just right. I should be ready to post some pics by tomorrow and test run by end of week. It is looking very nice. I will get some pics and show the progress.
 

snelson203

New Member
Mar 20, 2014
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0
Philadelphia Area
Here is the work in progress. Engine is mounted- after grinding, drilling, tapping and filing...not exactly out of the box and onto the bike. Rag joint really came out nice- centered and no wobble. I am having an issue with some wobble in the 4G transmission and started another thread on that. It's coming along.
 

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