Weed Eater mini bike questions

[2StrokeMama]

Well, I have come here to find some more information on how I am going to build my 2 weed eater engines, brand new, into a pair of mini bikes. I have already decided to do chain driven setups, so don't try and convince me otherwise lol. These will be more the novelty thing and I plan to make them look super cute and awesome for the family, siblings and friends to dink around on in the summer
These bikes won't have pedals, just foot pegs. Brakes will be installed.
My concerns/questions , are will it be possible to modify these in a way that when you pull the throttle, the clutch can engage and take off. When I picture this in my head, I am picturing that either you would need to pedal the bike no matter what to stop it from stalling or if using no pedals would need to run along side it and jump on/throttle same time before it stalls....
Any help and tips would be great as this is my first weed eater MB build
~~~ 2StrokeMama ~~~

 

[Steve Best]

Most weed eaters have centrifugal clutches that engage with rpm, so it engages as you rev them up.
Keep the gear ratio low to help the clutch survive.

 

[2StrokeMama]

I have read that only once compared to what I heard ^^^ I thought most eaters have a shaft that spins even tho the throttle is not being pulled?
I understand centrifugal clutches mostly on scooters , so I'm a little confused on this one.
Can you show me an example of a weed eater WITH the centrifugal clutch? Because the one I have has a pull start , but it spins without the throttle.

Gear ratio will be low since the bikes will be very tiny.
Thank you for your reply!!

 

[Steve Best]

Ryobi SS30 (RY30002) String Trimmer for an example
http://www.ereplacementparts.com/images/ryobi/RY30002.pdf
You are right. Many of the smaller weed whackers do not have centrifugal clutches.
Many of the medium to larger ones do. Can you shop around?

 

[2StrokeMama]

Yes, I can look around thank you.
I will stick to the larger 30cc ones forsure then. I suppose there's no way to really tell from looking at the box? Do you think it would say?

 

[5-7HEAVEN]

Can I make a suggestion?
Don't buy 25cc weedeaters.
Buy two of these:
http://www.ebay.com/itm/TANAKA-Util...ash=item4401c052d5:g:G7YAAOSw9k5XPnI8&vxp=mtr
These are high-quality super dependable 22cc engines at fantastic prices.

And they have acceptable 54mm clutches.

 

[5-7HEAVEN]

For the sake of quick installation and having fun rides in a few hours, buy this:
http://www.staton-inc.com/store/index.php?p=product&id=1775

I know you had your mind set on chain and gears. JMO, unless you're REAL handy, you'll never get your engine installed and running WELL as quickly as friction drive.

My first five bikes had friction drive. All of them were complete and running in one day.
And they ran for hundreds of miles each.

 

[Steve Best]

My first motorized bike was a Grubee Skyhawk. It went together as the directions implied.
It ran for 1500 miles of experimentation and high reving speeds and modifications.
A wristpin circlip failed from hours of 10,000 rpm. Imagine if I rode it as intended?

You friction drive guys, you're always rubbing your tires!

Seriously 5-7 Heaven, that TANAKA trimmer looks like a great tip. They are a very good motor.
Now about all this tire rubbing...

 

[2StrokeMama]

Lol, I've never made one of these bikes before, but for some reason when I see that peg rolling on the back of the bikes, it just makes me wanna use the chain drive, I can't really explain, but if one were to create specific mini bikes made from these platforms , I feel like the friction drive would fail before the chain... assuming everything Else is on point.
I also want the "look" of a mini bike....
I do own a skyhawk aswell, it sits on my chopper bike. I'm not a big fan of pedalling to engage the clutch so these tiny motors seem to do the trick.

Regarding those Tanaka trimmers you posted, they have the centrifugal clutch?
I really AM set on this chain drive I know it is possible! Maybe I should post a pic of what I'm going after... guaranteed you fellas have seen it online...

 

[2StrokeMama]

IMG_0810

• 2StrokeMama
• Apr 18, 2017
• 13