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How to add a sprocket on a weed eater shaft

Post all about your home built rides here. Weedwacker motors, lawn mower engines ect. This area is for non kit builds


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  #1  
Old 01-06-2011, 09:19 AM
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Default My first weed eater bike project

Happy new year to all!!

I have this weed eater bike project I need some help with.

Got this Homelite Mighty Lite 26cc HLT26CDNB weed eater to put on the rear of fold-able bike I have collecting dust. I thought this homelite model have a clutch in it, unfortunately none, must be an older model as I see the specs online for the HLT26CD having clutch.

Is it possible to add a clutch on this?

Anyway, I got the casing removed and found the shaft having a square hole. I will use an HT 10tooth sprocket and 44tooth for the big one. Not sure how the engine will handle this though.

What tools/method can I use to put the spocket on the shaft? Sorry I am not mechanically inclined

Or will this better with a friction drive setup in regards with the motor power output?

On this I will use a bike peg I suppose.

Thanks in advance for the replies guys.

Jerico

Last edited by Jeco; 01-06-2011 at 10:52 AM.
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Old 01-07-2011, 05:53 AM
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Default Re: How to add a sprocket on a weed eater shaft

Got some slotted angle bars for mounting, I think this will be an easy mount.
Waiting for the sprockets to be delivered hopefully tomorrow, if not I will do Friction drive setup. Less cost.
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Old 01-07-2011, 01:05 PM
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Default Re: How to add a sprocket on a weed eater shaft

Can you post up some pics? I've never heard of a weed whacker that didn't have a clutch, so it would be helpful to see what your engine looks like.

I built a boat motor out of a Ryobi weed whacker, and it works well, so it would be fun to assist you with your build.

Erich
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Old 01-07-2011, 06:20 PM
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Default Re: How to add a sprocket on a weed eater shaft

HI,

I think you will need more gear reduction than the roughly 4 to one ratio you will end up doing what you are thinking about....

The little Chinese frame mount 2 strokes (center mounts) have an internal primary reduction of about 4 to one (it's hidden under the clutch cover) THEN they drive to approximately another 4 to 1 reduction (the front sprocket to the rear sprocket)....for a total gearing reduction far beyond your roughly 4 to 1 overall ratio.

Friction drive will give you a better chance at working faster and easier but it may eat tires more often.

You could try a jackshaft to get better gearing with a chain drive.

The smallish displacement of the weed eater engine may hamper performance somewhat tho....BUT then again I was thinking of adapting an R/C Nitro .21 engine (3.5 CC!) for bike use!

Sounds like an interesting project....Good luck and keep us posted!

Have fun!

Andrew
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Old 01-07-2011, 10:20 PM
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Default Re: How to add a sprocket on a weed eater shaft

There is a company called www.whackerengines.com, which sells an adapter for 31cc ryobis, that could be used to install a cog of some kind, or maybe a fairly narrow roller.

It might be possible to use a belt pulley and a double rim, whizzer style, sort of like Lowracer did with his BMP kit.

Wackerengines

http://wackerengines.com/homelitehubls1.JPG

Last edited by happycheapskate; 01-07-2011 at 10:24 PM.
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Old 01-08-2011, 07:10 AM
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Default Re: How to add a sprocket on a weed eater shaft

Great find Happy. That's gonna help a whole bunch of folks. TY

Wackerengines

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Old 01-10-2011, 01:33 AM
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Default Re: How to add a sprocket on a weed eater shaft

very nice find indeed happy!

as suggested by Andrew and some search in youtube, my homelite is now with a bike footpeg for now. The chain and sprocket came a bit late.

@erich
it does not have a clutch as seen in the pictures attached. That's how it looked like out from the case, with a small shaft that is now inside the peg.

On mounting, screws from the casing are a bit small. I'm not sure a similar size bolt/nut will do. Should I make the holes larger for a bigger bolt/nuts?
I'm afraid the holes will break with the motor and tire's force, or this is strong enough?

Thanks guys!

Jeco
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Last edited by Jeco; 01-10-2011 at 01:37 AM.
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Old 01-10-2011, 11:36 AM
Erich_870 Erich_870 is offline
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Default Re: How to add a sprocket on a weed eater shaft

Quote:
Originally Posted by Jeco View Post

@erich
it does not have a clutch as seen in the pictures attached. That's how it looked like out from the case, with a small shaft that is now inside the peg.
Well, you learn something new everyday. How will you start it with the pull cord removed?

Here's my ryobi clutch



Erich
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Old 01-10-2011, 11:39 AM
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Default Re: How to add a sprocket on a weed eater shaft

It'll be a pedal/push start.

Good that you have a clutch on your ryobi, but some say these kind of motors are better off without the clutch, more power without it.
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Old 01-10-2011, 11:44 AM
Erich_870 Erich_870 is offline
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Default Re: How to add a sprocket on a weed eater shaft

Quote:
Originally Posted by Jeco View Post
It'll be a pedal/push start.

Good that you have a clutch on your ryobi, but some say these kind of motors are better off without the clutch, more power without it.
Funny you mention that they sometimes are better with out a clutch because I had to build a clutch lock-up plate because the clutch was always slipping and over heating.





Erich
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