Kickstarter For Briggs Motors

msrfan

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Sep 17, 2010
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Ever since my Friend Anthony, ''briggsbiker'', made a kicker for his motorized bike, I've been wanting to make a better one. A lot of small engines of all makes have a 4 bolt pattern on the PTO side to attach pumps and other equipment. And some also have a 1/2'' 20 thread hole to the right that Trimmer edgers use for their setup. So I found engineering drawings locating the exact dimensions of the crankshaft hole in relation to the 5 holes I just described. I cut a base plate from 1/4'' steel in a shape to bolt to the engine using the 4 threaded holes. I made a freewheel with a 3/4'' keyed hub welded into it for an earlier project that never got used, so I used it for my Kickstarter. Then I made a blueprint for a segment gear to mesh with it and pivot at the center of the lower right side cover mounting hole. My grandson laser cut a piece from my blueprint and I had all the basic parts to fab the rest.





I bolted an arm to the segment gear, attached a folding footpeg for the kicker, along with a few spacers, bushings and brackets to complete the assembly. Added a return spring and began testing.





Everything is on Dave's chopper style bike that is on a build thread in the cruiser category. Still needs some refinements but looks like it's going to work fine. And I have plenty of room for the pulleys and belt for the primary drive as well as an exhaust pipe.


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Jan 17, 2015
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Ever since my Friend Anthony, ''briggsbiker'', made a kicker for his motorized bike, I've been wanting to make a better one. A lot of small engines of all makes have a 4 bolt pattern on the PTO side to attach pumps and other equipment. And some also have a 1/2'' 20 thread hole to the right that Trimmer edgers use for their setup. So I found engineering drawings locating the exact dimensions of the crankshaft hole in relation to the 5 holes I just described. I cut a base plate from 1/4'' steel in a shape to bolt to the engine using the 4 threaded holes. I made a freewheel with a 3/4'' keyed hub welded into it for an earlier project that never got used, so I used it for my Kickstarter. Then I made a blueprint for a segment gear to mesh with it and pivot at the center of the lower right side cover mounting hole. My grandson laser cut a piece from my blueprint and I had all the basic parts to fab the rest.





I bolted an arm to the segment gear, attached a folding footpeg for the kicker, along with a few spacers, bushings and brackets to complete the assembly. Added a return spring and began testing.





Everything is on Dave's chopper style bike that is on a build thread in the cruiser category. Still needs some refinements but looks like it's going to work fine. And I have plenty of room for the pulleys and belt for the primary drive as well as an exhaust pipe.


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Nice!! Make em up. I'll like one. Only thing better is that '2stroke' elec start 'Bullet' engine.
 

xseler

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Apr 14, 2013
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I've got this sitting in my garage --- just waiting for enough inspiration to build around it.



It's a 1932 Briggs washing machine motor. It runs, but needs a new carb. Old one is toast. Doesn't look like it would be hard to adapt a NT carb to it.
 

Dan

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May 25, 2008
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Like all your stuff, MSRFAN, awesome!!!

Working on a cvt located behind the engine. Add that to your as usual brilliance, would be killer approach.

Gonna PM ya. But you thinking of producing for the public? Folks would go bat spit crazy for that. Gets rid of pull start and shaves what, 3 inches off width?

My cvt is designed to be universal. Sort of a transmission in a bolt on box.

I just wanna build cool stuff. But having rode the short bus, wearing a helmet on the road less traveled on the way to the school of hard knocks....
Am in need of adult guidance, snork.
 

Dan

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Do you think, or how hard to build a kick-ar right in to engine mounting plate?

Using the shaft on the Right?


Dang! That would be awesome! Any HF, Briggs etc engine that could fit in a frame...
CVT 17:1/+10% OF RPM, kickstarted =PURE MB JOY!!!!
 

Dan

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For new folks, MSRFAN is an important originator of DIY, MBs. After coming up with innovative ways to mount 4 smoke engines, he (at his own expense) printed how2's and mailed (snail mail ed) em to any one who asked. Never tried to profit and has been here helping folks from the beginning of this forum and pretty much the hobby. (Some might say crazy, but hey)

Honestly, one of the great Grandpa's of what MBs are today. An awful lot of mass marketed stuff from China looks Like his work. (just sayin')

Really, one of the good guys and historically great and influential creators of taking perfectly good bicycles, strapping an engine on em. And if we live, post about it.
 

msrfan

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Sep 17, 2010
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Southern California
Thanks Curt, Tony01 and scratchbuilder, it was a lot of fun engineering this mechanism and I still need to give it a long range test. I'll post the progress when I get the bike on the road.
 

msrfan

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Sep 17, 2010
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Thanks Dan, always glad to help to promote the hobby. As far as mounting a kicker to the engine plate, as long as there's no elongated holes for engine adjustment it may work. The whole idea for me was that most industrial motors come with that 4 hole pattern around the PTO making a universal base plate feasible if it's attached directly to the engine. Precision fitting the segment gear to the ratcheting pinion gear is key to a smooth working kicker. Unfortunately, they're all on the left side of the engine. The pinion gear I put together by turning down the outside of a small sprocket until it fit nicely into a freewheel sprocket. Then had the two tigged together. I had to take the freewheel apart, then reassemble it after welding. As far as producing them, I wouldn't mind supplying the base plates to experienced fabbers, but most may not be able or willing to go to that much work, and I don't know where to buy ratcheting sprockets already made up. Once you figure what pinion gear you're going to use, you have to fit a segment gear to it. I really like people to capitalize on my designs and take them a step farther. It's always a learning experience seeing other members projects and using some of the technology they use.
Right side kickers would be ideal but most engines don't have room inside the flywheel. But a ratcheting sprocket or gear where the flywheel nut is would work using your idea of a engine base plate mounted pivot for the kick arm. Have to be pretty beefy out that far. I'm going to work on that design and see what I can come up with. Sometimes it just takes a question or two to get inspired.
But back to your question about producing for the public. I have 4 or 5 Briggs bikes I may want to retrofit with my kickstarter before I consider it. Besides, the long arm with the folding peg won't fit everyone's design. I had to work it around the kickstand, pedal crank and exhaust pipe. And anyone with a 3D clutch can always pedal start their bike. I really like a bike you don't have to pull start. That's why I've never used a Comet belt drive, but if my kicker works fine, I can start using them without a pull starter.
 
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Dan

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Mind is realing, MS!

Was thinking a chain driven deal so could be truly universal?

Using a comet style CVT is a great solution and I agree, always feel silly pull starting.

What's the word for a one way sprocket? So after kicked, the rt side of the shaft can spin...


This could be so Kewl!
 

curtisfox

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Dec 29, 2008
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Ya! Dan you got things going, mind is a thinking. All kinds of options if there is room, right, left even on jack shaft, would depend on the drive setup.........Curt
 

Dan

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That's a thunk, Curt!

Would have to be a shaft any way. So having the option of sprocket on the left would open it up to other applications. Just have to extend shaft 1/2 inch or so.

Thinking the horseshoe shape of the engine mounting plate. The backseat threw it to words the rear....

Kicker on rt side. Chain could go to PTO side or pull side.

I've experimented and have had no ill effects from removing the forced air components. Engines kept cool enough as is with wind and ambient cooling.

But is that part of the flywheel on most Engines?

Guess it wouldn't matter or be dangerous just fine just hanging out and spinning. And could fab some sort of cover........

But cool thunk, Curt.

Sorry about typing out loud on your thread, MSRFAN.
 

msrfan

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Sep 17, 2010
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Okay, I figured out a way to move the kicker to the right side but have to re-design the mounting plate and segment gear. Don't know if I'll do it on this build, but definitely will in the future. I'll mount a tube on top of the rear mount like Briggsbiker did years ago, and run a shaft through it connecting the segment gear to the kicker on opposite sides. That way I won't have to deal with the flywheel. I can weld studs to the bottom of the tube for engine mounts.
 

curtisfox

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Dec 29, 2008
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I got one of them old engines! Why didn't i think of that. Sounds KOOL, and should work good..........Curt
 

indian22

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Dec 31, 2014
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MSR I've not commented on your talent in the past but have none the less noted it. This kick start is a really impressive piece of work. Rick C.