Torque?

[Sidewinder Jerry]

Let me chime in on this 4 strokes are meant to be ridden at max horsepower rpm but should be hitting at least max torque rpm when under a heavy load. This is where a shifter bike and tachometer come in handy. A tach/hour counter also helps to maintain maintenance schedules.

 

[Sidewinder Jerry]

Well, i am preatt sure that 4s does have more torque. I had 80cc 2 Stroke and in comparison Huasheng 142f have a lot more torque. I cruise on huasheng 35mph.

From the looks of the bike in your picture you use 26" tires. Your engine max hp rpm is 6800. On a level road, to go 35 mph on 26" tires at 6800 rpm would require a total reduction of 15\1.

Unless you and the bike's total weight is under a 150 lbs, performance engine mods have been done, and you live in the flat lands; it isn't advised to have a total reduction lower than 16\1. Even then you're going to need a lot of pedal assist to get going.

With the 142 engine using 26" tires an 18\1 minimum reduction would be more appropriate. Giving you a top speed of 29.2 mph. If you live where there are steep hills you're going to need even lower reductions. My shifter bike's reduction range is 66.79\1 to 16.25\1

 

[JuraTyKokotko]

From the looks of the bike in your picture you use 26" tires. Your engine max hp rpm is 6800. On a level road, to go 35 mph on 26" tires at 6800 rpm would require a total reduction of 15\1.

Unless you and the bike's total weight is under a 150 lbs, performance engine mods have been done, and you live in the flat lands; it isn't advised to have a total reduction lower than 16\1. Even then you're going to need a lot of pedal assist to get going.

With the 142 engine using 26" tires an 18\1 minimum reduction would be more appropriate. Giving you a top speed of 29.2 mph. If you live where there are steep hills you're going to need even lower reductions. My shifter bike's reduction range is 66.79\1 to 16.25\1

I live in very hilly area. And i did some mods ,

 

[Sidewinder Jerry]

I live in very hilly area. And i did some mods ,

There are bumps in the road (under 10% grade) then there are hills (20%+ grade) lol. There are a few things you can do to the engine to increase its performance slightly; even then it's not recommended to push the142 beyond 7500 rpm. At 7500 rpm on 26" tires, it'd require a 16.57\1 reduction to do 35 mph on a level road. That reduction even for a lite person should never be used to climb any hill over a 5% grade. My level ground take off gear is a 36.67\1 reduction.

Now if you're talking about 35 mph going downhill, that doesn't count. I've hit speeds of 45+ downhill. If you are in steep hill country; I strongly suggest getting a Strumey Archer 5-speed internal geared hub to use as a jackshaft transmission.

 

[JuraTyKokotko]

There are bumps in the road (under 10% grade) then there are hills (20%+ grade) lol. There are a few things you can do to the engine to increase its performance slightly; even then it's not recommended to push the142 beyond 7500 rpm. At 7500 rpm on 26" tires, it'd require a 16.57\1 reduction to do 35 mph on a level road. That reduction even for a lite person should never be used to climb any hill over a 5% grade. My level ground take off gear is a 36.67\1 reduction.

Now if you're talking about 35 mph going downhill, that doesn't count. I've hit speeds of 45+ downhill. If you are in steep hill country; I strongly suggest getting a Strumey Archer 5-speed internal geared hub to use as a jackshaft transmission.

i didnt measure downhill. but hills in my area are 10 - 14% grade. The huasheng is really doing a good job. And i plan on buying shifting kit.

 

[ImpulseRocket]

The 4 strokes make more torque, but are limited to about half the practical RPM range that an equivalent 2 stroke motor makes. It's not really the fact that it is a 4 stroke that does this, but the way the head and cam are designed to create that power. Since most stationary style forced cooling engines are meant to live long lives running at happy stable RPMs in all conditions, it makes the most sense to have a lot of low rpm power.

The 2 stroke kits... not so much. In fact, properly tuned 2 strokes can produce a stupid amount of torque at low rpm's too. Just like the 4 strokes, it just depends on how they decided to setup the way they are tuned to make that power.

If a 49cc 4 stroke makes 1.5hp and has a max RPM of 3600, and the 49cc 2 stroke also makes 1.5hp, but has a max RPM of 7200 (For sake of argument), and it just so happens the 2 stroke makes half the torque of the 4 stroke... The 2 stroke can have double the gear reduction, both bikes will achieve the same speed at their respective maximum RPM, and the torque delivered through the rear wheel to the ground will be numerically the same you just then have to ask yourself if you prefer the smell of 2 stroke oil or not.

The only real advantage 4 strokes have over 2 strokes at the end of the day is efficiency, and sounding like a lawnmower instead of a weedwacker.

 

[FrizzleFried]

There are a couple other real advantages...

• Reliable pull-start - though this could be an advantage or disadvantage depending on preference I suppose.
• Fill-and-go fuel ups out on the road. I doubt a single 2-stroker will argue with this advantage...

EDIT: Oh... and twist-and-go for those who have no idea how to use a clutch. For those of us who do... this is a bit of a disadvantage though...

 

[ImpulseRocket]

There are a couple other real advantages...

• Reliable pull-start - though this could be an advantage or disadvantage depending on preference I suppose.
• Fill-and-go fuel ups out on the road. I doubt a single 2-stroker will argue with this advantage...

EDIT: Oh... and twist-and-go for those who have no idea how to use a clutch. For those of us who do... this is a bit of a disadvantage though...

The pull start thing doesn't bother me. It's awkward to do while riding, and thus means you have.to be stationary to start it up. The 2 stroke bump start is easy if the engine tune is good.

The fuel ups is true. To me, not a deal breaker though. It's never held me up, and the advent of folding fuel cans really makes it possible to carry a can to mix oil on the go.

Other advantage of the 2 strokes is size. The 4 strokes are wider and a tad heavier.

Really just comes down to what you want to deal with. I like both for different reasons.

 

[Chainlube]

I like both for different reasons.

I like both to because.....well, they're engines.

 

[Sidewinder Jerry]

The pull start thing doesn't bother me. It's awkward to do while riding, and thus means you have.to be stationary to start it up. The 2 stroke bump start is easy if the engine tune is good.

The fuel ups is true. To me, not a deal breaker though. It's never held me up, and the advent of folding fuel cans really makes it possible to carry a can to mix oil on the go.

Other advantage of the 2 strokes is size. The 4 strokes are wider and a tad heavier.

Really just comes down to what you want to deal with. I like both for different reasons.

Many like me have extra-large gas tanks (5 quarts). I use one because very few gas stations sell ethanol-free gas. I will not run ethanol-mix gas in any of my small engines.