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4 Stroke Bicycle Engines & Kits 4 stroke engine kits are great if you want reliability or do not want to mix your oil and gas. Learn from each other how to get the most out of your 4 stroke bicycle engine


Clutch problems on 4 stroke 49cc engine kit

4 stroke engine kits are great if you want reliability or do not want to mix your oil and gas. Learn from each other how to get the most out of your 4 stroke bicycle engine


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Old 12-27-2012, 03:17 PM
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Default Clutch problems on 4 stroke 49cc engine kit

Hi there guys,

Im having some problems on a 4 stroke engine kit.

The first problem was burn completely the clutch, after 5 miles of use.

It uses a 11T front sprocket. I thought it was because the 40T sprocket, changed for 44T sprocket, bought a new clutch kit on a local store, went for a ride, and it seems the clutch is spinning a lot..in a little hill, even with max throttle, the clutch doesnt "stick" on at all..

Im not heavy (around 150 pounds), the bicycle has about 60 pounds...

I was thinking in the carburetor...if the carb is not tuned properly, it may not accelerate as it should, and the clutch springs does not expand..

What you guys think?
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Old 12-27-2012, 03:22 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

You should be able to tell if the engine is revving up by the noise. If the revs increase and nothing engages, then it's the clutch.
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Old 12-27-2012, 03:34 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

At no load (on stand) it is revving good. It revs until it reaches a mid rpm (up hill) but down a hill it does 60km/h..at striaght road, does 45km/h
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Old 12-27-2012, 04:10 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

Quote:
Originally Posted by DanielMaia View Post
Hi there guys,

Im having some problems on a 4 stroke engine kit.

The first problem was burn completely the clutch, after 5 miles of use.

It uses a 11T front sprocket. I thought it was because the 40T sprocket, changed for 44T sprocket, bought a new clutch kit on a local store, went for a ride, and it seems the clutch is spinning a lot..in a little hill, even with max throttle, the clutch doesnt "stick" on at all..

Im not heavy (around 150 pounds), the bicycle has about 60 pounds...

I was thinking in the carburetor...if the carb is not tuned properly, it may not accelerate as it should, and the clutch springs does not expand..

What you guys think?
What kind of gearbox do you have?
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  #5  
Old 12-27-2012, 04:10 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

this one:

http://t4bmotorsports.com/uploads/Pr...0/IMG_0872.JPG
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Old 12-27-2012, 04:26 PM
Fugi93 Fugi93 is offline
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Default Re: Clutch problems on 4 stroke 49cc engine kit

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Originally Posted by DanielMaia View Post
Do you have a picture of your bike? I always wondered how the dax gearbox was able to line up. It is very difficult to believe that you could ruin a clutch in 5 miles! Are you running an oil in the gearbox?

Last edited by Fugi93; 12-27-2012 at 04:34 PM.
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Old 12-27-2012, 06:08 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

Those gear boxes only have a 3:1 reduction I believe.

So it needs a rear sprocket that has something like 50t to get good reduction for it to accelerate properly
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Old 12-27-2012, 06:45 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

Yes it is. 9 tooth sprocket just after the centrifugal clutch, 27T on big wheel; 11T front sprocket, 44T on the wheel
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Old 12-27-2012, 06:56 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

I heard a 54t for the rear wheel is a good ratio.

If you keep that 44t your just going to keep burning up clutches.
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Old 12-27-2012, 06:59 PM
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Default Re: Clutch problems on 4 stroke 49cc engine kit

thank you guys,

i will also do some sanding on the clutch drum, it is completely sleek and polished, and may not be good to attach on the clutch pad
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