Will 4 stroke let me ride from standstill instead of starting out pedaling?

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masterfowler

New Member
Aug 31, 2011
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charleston
To be a bit clearer, I'm 6'3, 200 lbs, my 2 stroke will immediatly shut off if I try and start going without pedaling some. I'm guessing this is the norm? Anyway, I've gotten into welding and I want to try and make my own frame and everything. However, I'd rather make something with no bicycling pedal system. Will a four stroke such as the Hua Sheng F142 49cc get me moving and require no pedal assistance. I understand it can be cranked to start, my question is does it have the power to get me moving from a standstill?
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
Yes and no.
All the 4-stroke kits seem to have centrifugal clutches so the transmission will engage on it's own. Low gearing will afford you the ability to take off from a dead stop at the cost of top end speed. If the drive train is geared for top speed then the clutch will slip alot when accelerating from a dead stop and most likely will end up frying the friction shoes in it.
A CVT system will give you the best of both worlds, excellent pulling power for dead stop acceleration, hill climbing and good top speed.
So far there are no CVT kits available though. Members here have built them up from parts available from vendors such as AGK, Bicycle-engines. com and 99cc and larger Harbor Freight Predator engines.
They are pull start though, no pedal starting here.
 

rustycase

Gutter Rider
May 26, 2011
2,746
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Left coast
IMO a 50cc 4 stroke should have plenty of torque for a start-off from a dead stop.

I am 6'2" and 250lbs and ride a box-stock 48cc skyhawk that is well run in, with factory gearing.

It will take me away from a stop sign on level ground, by slipping the clutch a tad, but I usually pedal a single revolution, rarely more.

My mab tops at abt 30mph with a 180lb rider.

Unless you have a specific reason, I would retain pedal capability, though.

Best
rc
 

wayne z

Active Member
Dec 5, 2010
1,743
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louisiana
The 79 and 99cc 4 strokes easily take off unassisted even with a simple cent clutch and jackshaft. I have 2 builds with them. They ar geared to get about 40mph at 5000 rpm. They have enough power to take off quite briskly even with sorta tall drive ratios.
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fredgold52

New Member
Dec 3, 2009
156
0
0
Illinois
My 4G kit with a 48 tooth sprocket lets me take off pretty well if I just give the bike a shove to get it moving. I'm 300 lbs. I have nothing but praise for these little HS 49cc engines. IMO, they are much better than one might expect considering the Chinese manufacture.

I'm going to change mine to a 44 tooth to get less rpm's at my preferred cruising speed, <20 mph.
 

The_Aleman

Active Member
Jul 31, 2008
2,653
4
38
el People's Republik de Kalifornistan
I have a Huasheng 49cc, 4G, shift kit with a 3-speed Sturmey hub, and it has more than enough grunt to pull off the line in 1st or 2nd gear.
But I pedal anyway. I'm 235lbs, in pretty decent shape, and I like my bikes and components to last.

I'm with those who say "if you don't want to pedal, buy a motorcycle or scooter".