Changing my 5G 49cc Huasheng engine to non-governed type

[jimfindlay356]

Changing my 5G 49cc Huasheng engine to non-governed type. I need to find parts to change the engine to a non-governed engine. can someone lead me in the right direction? Jim

 

[DieselTech]

The picture of your engine is a governed 144fhausheng, notice how square/boxy the one in your pic is. It should be governed to 6800 rpm's. You need to find rounded style coil/magneto & matching flywheel. It looks like this.

 

[michael whiteman]

This might be what you're looking for

[How-To] Ungovern HuaSheng 142f

I'm working on ungoverning my HS 142f and since I haven't seen any "how-to" post which I'll find useful, here is mine, for now "work in progress". I'll keep updating this first post as I can invest hours on this. Special tools needed: - Balancer Puller (to pull the flywheel, learned kind of the...

motoredbikes.com

 

[Cannonball3]

Might make a bracket like the old Briggs when you swapped flywheels, to move the cdi to the proper timing with the existing flywheel.

 

[michael whiteman]

Hey Cannonball3.........I think you meant to say: move the existing (factory) CDI to work with the new flywheel. You would have to measure the difference of the trigger position between the two CDI units and make the mounting bracket with this offset. Make sure you mount the offset counter clockwise in relation to the flywheel.

 

[michael whiteman]

I worked in a speed shop during the muscle car era and could not tell you how many hundreds of distributors I recurved. I have never seen these two flywheels and CDI units side by side, but I do know how ignition timing works.

I am assuming, and we all know the acronym for this, that there is no computer type circuitry within this CDI unit. Simply two coil windings that could be easily verified with an OHM meter. If I am wrong, stop reading this now.

Measure the distance from the trigger pad to the mounting hole on the CDI and compare the resistance (OHMS) of both the primary and secondary windings. My guess is that both CDI units are the same. Notice on the flywheels the different location of the trigger magnet. This difference is the amount advance in the timing and will be copied onto the bracket you'll make.

Advancing the timing on an engine that is running in a less than ideal condition will make more power and better fuel economy.
I'm sure this is the way the manufacturer slows this engine down, probably to meet the emission standards. So basically all we need to do is advance the timing to make all things better.

It does not matter where the trigger point (magnet) is located on the flywheel. We know it's working. To advance the timing we need to make the spark happen sooner. As Cannonball3 suggested just make a bracket and relocate the original CDI without changing the flywheel. Make sure the CDI is mounted counter clockwise to where it is now.

Having never taken my engine apart, I do not know whether it is possible to mount an offset bracket on the engine block. You'll have to tell me. All of this is only food for thought.

One last thing. It amazes me that the valve train in these engines rev as high as they do. From a design point they are the cheapest (least expensive) thing to make. One lobe on the cam. Really??? Who does that? Personally I would not think about making these mods unless I was intending on balancing this engine also. How fast do you want to go? The pain from the pavement increases by the square of your speed.

 

[Cannonball3]

When racing karts we lapped the flywheel and ran keyless. This is easier to do if you know exactly where the cdi fires.
We set the timing in the hole using and adjustable piston stop. If one found exactly on the cdi unit the magnet fires it (we new that on the Briggs) then its a simple matter to move the old flywheel to that position on the unlimited cdi. Hold all in place and lock the flywheel.

 

[darwin]

Michael W., dunno why a pickup coil from a Honda GXH50 will not work on a HS 142/144f or visa versa. Each pickup looks the same.

 

[michael whiteman]

There is a whole range of experience levels with the folks on this forum and I never know to whom I am making a point. You, Cannonball3, definitely know what you're talking about from first hand experience. I have never disassembled my engine.

I see no reason Darwin, why the Honda CDI will not work. I only know you'll pay more if it says Honda.

 

[Cannonball3]

Honda rates this engine at 7000rpms with max torque in the mid 4000s. Maybe the Honda cdi is limited? The ignition
would be the only way to limit it since there is no mechanical governor. My HS cruises in the low 5k range at 30mph in 6th gear. It will rev higher but its in/around its torque peak and pulls well there. Spinning the little engine into the unlimited ranges has got to be hard on the stock valve train. Personally Im glad mine is limited, I would hate to blow the little thing up.

 

[Cannonball3]

So not trying to hack this thread, but thought I would add some pertinent info. I just finished break in on the HS and also a final ratio change on the shifter build. I have an accurately set up speedo and a tach. With the lowered over all ratio I was surprised at the results. The engine turned 6720 max rpms. It has the square cdi. Maybe its limited at 7k?
Pretty sure the tach is right. Interestingly its faster in 5th of 7 gears. 6&7 make nice relaxed cruising gears in the max torque band. Max speeds were 36-5th, 33-6th, 31-7th. Interesting little motor. I honestly think it had a bit more as I ran out of road on my test circuit. Maybe its a 7k engine.