Ruttman minibike build with 5hp Briggs flathead

#1
Hi, I'm working on a Ruttman Minibike with a 5hp flathead Briggs. Could someone point me to an exhaust header with mabie a silencer & brace?
I sold a lil Indian project awhile ago & I bought a wrong Header for it, The flange was too big & clocked wrong. I'd like to try & get a right one
this time, Thanks.
 

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Minimichael

Well-Known Member
#2
Hi, I'm working on a Ruttman Minibike with a 5hp flathead Briggs. Could someone point me to an exhaust header with mabie a silencer & brace?
I sold a lil Indian project awhile ago & I bought a wrong Header for it, The flange was too big & clocked wrong. I'd like to try & get a right one
this time, Thanks.
Great looking engine you got there. Is that a custom clutch guard? :cool:
 
#3
Kinda? The Units a manual clutch from 3d motorsports. I had to notch the aluminum guard corner out to fit with the engine starter & jb welded a strip of aluminum bar bridging across the inside of the corner at a 45. Then taped the outside shut again & filled up the inside solid with more jb weld & sanded & filed the outside round. It used to be red with the 3d motorsports logo but I used paint stripper to get it down to metal & painted it with black vht crinkle coat & then used my heat gun to get it all crinkly :)
 
#6
Thanks!

Krinklepaint matches good with a small black gator skin seat "vinyl" I used to have on the lil Indian
& Indian head sawtooth tires. Guy on eBay will make you a custom seat to order. Never should of sold that thing....

What I originally had in mind Was this stainless steel straight pipe header I saw. The holes I believe are 1-1/2 "
looks like AR Sport LIC used to sell one But no longer. Looks like raptor parts work? Then I found a video & now I think
I like his style better. I believe I found the vender's site & the header in the vid looks like his 98-mc model. I'll try calling
tomorrow, I think I'm in a different time zone then him, I'm up in W.A. state & His site says Mountain time. Anyone else have a good
source?

https://www.robertsonstorquetubes.com/briggsflatheadraptor?page=2

 

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Minimichael

Well-Known Member
#7
Thanks!

Krinklepaint matches good with a small black gator skin seat "vinyl" I used to have on the lil Indian
& Indian head sawtooth tires. Guy on eBay will make you a custom seat to order. Never should of sold that thing....

What I originally had in mind Was this stainless steel straight pipe header I saw. The holes I believe are 1-1/2 "
looks like AR Sport LIC used to sell one But no longer. Looks like raptor parts work? Then I found a video & now I think
I like his style better. I believe I found the vender's site & the header in the vid looks like his 98-mc model. I'll try calling
tomorrow, I think I'm in a different time zone then him, I'm up in W.A. state & His site says Mountain time. Anyone else have a good
source?

https://www.robertsonstorquetubes.com/briggsflatheadraptor?page=2

That thing is gonna rip! I really like the idea of a manual clutch, too. Glad you mentioned vht... I'd forgotten where I'd seen crinkle paint before. Someday I want to do a shroud in crinkle, maybe even the whole block. How will you power the starter? Have a battery source already picked out?

I did my most recent Briggs header in stainless flex pipe...
https://oldminibikes.com/forum/inde...ure-briggs-61102-upgrades.176556/post-1297046
PXL_20220911_024311544.NIGHT~2.jpg
 
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#8
Nice.

Sealed Battery sideways under the gas tank? I have a 1967 Honda s90 with a 6v system & was sick & tired of the battery always going flat.
Bought a gell cell Moto-Batt brand battery & it works way better. Also had an electric razor scooter that I added extra batteries & a kit from over volt scooters once & it just used sealed lead acid batteries & they are about the right size for that space. I'm not sure if I need some sort of solid state charge regulator for it or if one off of any old riding mower will work. Also not sure if I need an ignition switch starter relay & an amp gauge & battery voltage gauge might be nice. Like the flex pipe stuff too, used for old gas powered Maytag washers so you wouldn't get smoked out... you'll get a kick out of what I did with the stuff awhile back :)

 
#9
I also need to figure out a toggle switch clutch lever, or a clutch lever with a safety lockout as the clutch is engaged at rest. I think some racing carts use these? Another Idea that came to me " & probably doesn't exist" is a jackshaft with a slip yoke or cog sleeve that slides on it to disengage it in neutral, mabie a jackshaft gearbox, idonno? Rokon & tule trooper trailbikes use a really neat british 3 speed Albion gearbox that has a disk cork clutch & the power input & output use a single shaft, very compact but they are rare and vintage...

LJ-Flexible-Coupling-Body.jpg

#1.jpg
 

Minimichael

Well-Known Member
#10
I also need to figure out a toggle switch clutch lever, or a clutch lever with a safety lockout as the clutch is engaged at rest. I think some racing carts use these? Another Idea that came to me " & probably doesn't exist" is a jackshaft with a slip yoke or cog sleeve that slides on it to disengage it in neutral, mabie a jackshaft gearbox, idonno? Rokon & tule trooper trailbikes use a really neat british 3 speed Albion gearbox that has a disk cork clutch & the power input & output use a single shaft, very compact but they are rare and vintage...

View attachment 294710

View attachment 294709
You get into some cool stuff! I have also been looking for a 2-speed clutch solution.
 
#12
So this mechanism would work perfect for a on/off toggling clutch lock lever for the manual clutch. I was actively looking for something like this & it "randomly" shows up in my YouTube video list, go figure.... Copy & Mount on the base of the clutch leaver & install pin on the swinging lever bit... I have found other locking clutch leavers or brake lock that just have a spring pin push button, but they are cheap chinesium stuff found on those motorized bicycle moped kits. Or there was another single leaver I saw for sale in Italy somewhere that was for some sort of rototiller implement that had a small ratchet catch release thumb button sticking out of the leaver handle that looked of a slightly higher quality, but still more trouble then it is worth. It would be nice if someone out there knew if this already exists or not tho, I would be interested in buying one.

 
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#13
I was also debating on using a band brake around the clutch bell. However, there are notches to accommodate the clutch discs. & the disc tabs are slightly proud of the bell. I could trim them & shrink fit a slim band over it all... I'm not sure what brakes it originally had, weather disc or drum but it doesn't have a welded on frame bracket anywhere for them & a brake will completely hide the mag wheel "gotta crash with style now"...
Anyway, just a thought.
maxresdefault.jpg
 
#14
Not my cup of tea, Uses allot of clutching & chains & a ratchet slip yoke???


How about a planetary gearset & a drum brake band to change speeds? Could this work & Is their an industrial Lego part out there that would plug & play??? It would be very ideal...

 
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