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

 

[Sidewinder Jerry]

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 it's a 7k engine.

The drop in speed Is due to engine strain. This is why I tell others lowering the reduction is only going to get you a higher speed to a certain point. These engines have a minimum reduction that can give you a maximum level ground speed. After that point, if you drop the reduction any lower it won't have the horsepower to make the engine go any faster, thus putting a strain on the engine.

Therefore, it sounds like anything beyond the 5th will be downhill gears for you.

 

[DieselTech]

Yeah I thought all the governored huasheng's were electronically governored/limited to 6800rpms. I'll believe that's what my manual says. Cannonball3 testing has open my eyes to a shift kit, wasnt expecting it to drop speed as gears increased. But I get with the hp. It's like when I dyno trucks for Caterpillar.

 

[Sidewinder Jerry]

Yeah I thought all the governored huasheng's were electronically governored/limited to 6800rpms. I'll believe that's what my manual says. Cannonball3 testing has open my eyes to a shift kit, wasnt expecting it to drop speed as gears increased. But I get with the hp. It's like when I dyno trucks for Caterpillar.

The same gearing principles apply to motorized bicycles as they do to pedal-only bicycles. There isn't any such thing as easy gears and hard gears on a pedal only bicycle. All gears are meant to be comfortable. If a gear is too easy or too hard to comfortably maintain a cadence (crank rpm) of 70-90 it means you're in the wrong gear. On pedal-only bicycles, you're the engine.

On my bike max torque is at 5000 rpm and the max hp is at 7000 rpm. Therefore at full throttle, if I drop below 6000 rpm I shift to lower gear. At FT if I'm going above 7000 rpm I shift to a higher gear.

 

[Cannonball3]

I think it's a torque thing vs rpm. It easily pulls the last two gears when in its torque band 4-5k, but as rpm increases in 6-7 the torque begins to drop off so the power to pull the higher gearing is not there or is dropping off. In 5th its unloaded and can wind on up. As I live in the flats 6-7 become cruising over drives. Kinda nice to cruise at 30@ mid 4k.

The gearing save for 1-2 is all overdriven. Take off thanks to the 34t low is at 29+:1 and pretty quick. Overall Im pretty pleased with the performance.

 

[Cannonball3]

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

The cdi modules are on ebay. Flywheels are scarce it seems.

 

[Sidewinder Jerry]

I think it's a torque thing vs rpm. It easily pulls the last two gears when in its torque band 4-5k, but as rpm increases in 6-7 the torque begins to drop off so the power to pull the higher gearing is not there or is dropping off. In 5th its unloaded and can wind on up. As I live in the flats 6-7 become cruising over drives. Kinda nice to cruise at 30@ mid 4k.

The gearing save for 1-2 is all overdriven. Take off thanks to the 34t low is at 29+:1 and pretty quick. Overall Im pretty pleased with the performance.

That isn't what's happening at all. Think of it like this on a pedal-only bicycle, if you were comfortably maintaining a cadence of 70-90 in say 3(5). Then change to 3(7) you're going to find it's much harder to maintain the 70-90 cadence. Well, the same thing is happening with your engine. The RPM is dropping due to the strain on the engine not due to some kind of overdrive.

The biggest danger of engine strain is wearing out your clutch

 

[Sidewinder Jerry]

On this matter, my advice is to set the high limiting screw on the rear derailleur to where it won't shift beyond the 5th gear. This'll reduce the amount of cross-chaining you'll be doing; saving wear on the chain, chainring, and rear freewheel.

 

[Cannonball3]

I dont quite understand strain. Are you referring to engine loading? Its torque that does the work. Ideally running an engine with in its max torque range is where you want to be for cruising. Thats mid 4k. Im using the specs from the GHX50, HS specs I havent found. I certainly wouldnt lock out 6-7 as they easily pull in the low 30s. A relaxed cruise is preferable to me than turning a thousand+ more rpms for the same speed. As to the clutch its fully engaged at 3600, I see no danger to it at mid 4k in 6-7.

 

[Sidewinder Jerry]

I dont quite understand strain. Are you referring to engine loading? Its torque that does the work. Ideally running an engine with in its max torque range is where you want to be for cruising. Thats mid 4k. Im using the specs from the GHX50, HS specs I havent found. I certainly wouldnt lock out 6-7 as they easily pull in the low 30s. A relaxed cruise is preferable to me than turning a thousand+ more rpms for the same speed. As to the clutch its fully engaged at 3600, I see no danger to it at mid 4k in 6-7.

At full throttle, you want to be where max hp is not where max torque is. If you're in a gear so high it pushes you below max torque rpm at full throttle; you risk burning up your clutch. If you want to cruise around at max torque rpm then be in the highest gear that something like 2/3 to 3/4 throttle shows max torque rpm on the tach.

So for those last 2 gears unless you're using them as downhill gears they're doing more harm than good.

 

[Cannonball3]

Out of respect for the OP and the content of the thread lets move this discussion to the thread on the bike in builds and pics

Thanks!