Centrifugal Centrifugal clutch and Start from zero (with no paddling)

Ronen

New Member
Joined
Dec 20, 2015
Messages
13
Hello, I have a 80cc chinese with regular clutch,
I want to buy a centrifugal clutch in order to start from zero without paddling
and I have some questions:

With Centrifugal clutch, when the engine is already running,
is it possible to just pull up the throttle from zero Mph and start rolling without touching the paddles at all?

And what is jackshafting and friction drive?

Thanks, Ronen
 


KCvale

Motorized Bicycle Vendor
Joined
Apr 18, 2010
Messages
3,518
Hello, I have a 80cc chinese with regular clutch,
I want to buy a centrifugal clutch in order to start from zero without paddling
and I have some questions:

With Centrifugal clutch, when the engine is already running,
is it possible to just pull up the throttle from zero Mph and start rolling without touching the paddles at all?

And what is jackshafting and friction drive?

Thanks, Ronen
To use a cent clutch you also need a pull start.
There are kits to convert these engines that way, but they require some expensive mods and not reliable.

All* 4-stroke engines have a pull start and cent clutch, and no, you never have pedal the things.
Give it gas and goes.

A shift kit (jackshaft) transfers the drive power to the right hand side so you have no left side chain and the engine power can use your bicycle gears.

Like this.



Pull start 49cc with auto clutch and a seven speed drive.
It will pull a wheelie from the the line in 1st and haul ass up to 40+ using the gears, and never pedal but you can if want.
 

Fabian

Well-Known Member
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Sep 8, 2009
Messages
4,522
You do not need a pull-start with the centrifugal clutch on the 2-stroke Chinese bicycle engine, but the pull-start is a handy item to have installed.
 

KCvale

Motorized Bicycle Vendor
Joined
Apr 18, 2010
Messages
3,518
You do not need a pull-start with the centrifugal clutch on the 2-stroke Chinese bicycle engine, but the pull-start is a handy item to have installed.
(sigh)
A centrifugal clutch is a one-way power transfer system.

When the power side of the clutch, where the engagement springs and shoes are mounted on the engine, they move out when they spin fast enough to engage the inside of a fixed size bell that connects to the rest of the drive system.

When the engine is not spinning fast enough to overpower the springs that hold the engagement shoes against the bell, they don't make contact or transfer power.

Your wheel side is connected to the bell side of the clutch.
It's just a piece of cupped metal that grabs the retracted clutch pads when they spin out fast enough to make contact, and passes the power on.

If the engine is off, the shoes are retraced and don't make contact with the bell.
You scan spin that bell all you want, it's not going to shrink in and grab the shoes.

You CAN NOT make a Cent. clutch transfer power from the output side, which includes trying to bump start a 2-stroke engine.

They are great benefit to an automatic clutch, I love them, but you need another way to start the engine regardless.
 
Last edited:

Fabian

Well-Known Member
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Sep 8, 2009
Messages
4,522
You are giving bad advise, as the commonly available centrifugal clutch CAN be used in pedal start mode on the 2-stroke Chinese motorised bicycle engine.

 

johnsteve

Member
Joined
Jul 20, 2015
Messages
114
interesting video, but where do you get the parts? Could you please put a link to the place where they can be boughtt?

also since I am a beginner at these type of things, I have to ask if wd40 is really good lubercation for the crankshaft extension bearing? I would imagine that the possibliity of burning up the bearing probable. would it now be possible to use a heavier lubercant?
 

Fabian

Well-Known Member
Joined
Sep 8, 2009
Messages
4,522
interesting video, but where do you get the parts? Could you please put a link to the place where they can be boughtt?

also since I am a beginner at these type of things, I have to ask if wd40 is really good lubercation for the crankshaft extension bearing? I would imagine that the possibliity of burning up the bearing probable. would it now be possible to use a heavier lubercant?
I have never said that you should be using WD40. Please read the description in the video.
You can simply Google pull-start pedal-start centrifugal clutch to find out where this item can be purchased, but i bought my centrifugal clutch through JN Motors.
 

skyash

Active Member
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Jun 26, 2015
Messages
755
All my bikes take off with no peddling a 66cc 26 Inc wheel 44 or 36 sprocket a 49 cc 4 stroke with a 20 Inc wheel 52 tooth sprocket and a 49 cc 2 stroke pocket bike motor 20 Inc wheel and 52 tooth or 44 sprocket. I like that you can start when pedalling on a 66cc a pull start is bad that it sucks to pull it on the go and it can brake my 49 cc 4 stroke just broke it's gearbox and it's new The chain inside come off I don't know y and is loose as now
 

Ronen

New Member
Joined
Dec 20, 2015
Messages
13
I have never said that you should be using WD40. Please read the description in the video.
You can simply Google pull-start pedal-start centrifugal clutch to find out where this item can be purchased, but i bought my centrifugal clutch through JN Motors.
With this clutch without a pull start installed, is it better to just pedal till it starts or pull the regular clutch and pedal and then release it?
 
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