Project: Bare Bones Bonanza

#1
I purchased this Bonanza MX Mini Bike last week with plans to freshen it up with powdercoat and new parts.
Unfortunately, It's missing it's original motor, wheels, tank, fenders, etc...etc..
On my budget, I can't aquire all the parts to restore this Bonanza to it's original condition, but I can make a nice (stripped down) mini that I'm calling a "Bare Bones Bonanza".
BEFORE:


My Plans include:
-Fix Frame
-Powdercoat
-New Wheels
-New Seat
-Motor 5+HP
-New Hardware/Controls/Etc...

Estimated Build Time: 3-4 months

Upon tear down I noticed that the right side jackshaft plate had been cut-off leaving only a mounting hole for the swingarm. Also, the motor plate had been poorly cut and layered with very thin 16-or-18 gauge steel. Holes for the footpegs were drilled through the motor plate on the left side and through the frame rail on the right side. :eek:


So I disassembled down to the frame and cut off the jackshaft/swingarm plates and cut off the multi-layered motor plate(s).
:grind:


I ordered some awesome replacement Bonanza jackshaft/swingarm plates from OldMiniBikes warehouse and bolted on a 5/8 threaded rod to keep everything square while there being welded on.


Today I dropped it off at a local welding fabrication shop. They are going to cut and weld on a new motor plate, the swing arm plates, some foot peg bungs, and fill/repair the holes in frame left by previous owners.

Should have the frame back next week. Then I will focus on rear wheel/brake/jackshaft/motor set-up and alignment.
 
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#3
Great start. Power plans?
Either a 5 hp Briggs or Honda or maybe the 6.5 Predator clone?

I'm not too sure how much clearance I need near -or- above the jackshaft. The Predator clone has that slanted cylinder head but then the Briggs fuel tank might interfere?
The jackshaft is actually alot closer to this old tecumseh motor than what appears in the pic
But I haven't really done any measuring yet.
 
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Oldsalt

Well-Known Member
#4
Good work! There is one advantage to working on a mini that has few original parts and the frame has been hacked on.....you are given a clean sheet to do what pleases you without fear that you are hurting anything. I vote you put any engine it in that you come across. A 5HP flattie or clone or whatever with the jackshaft will make it perform!
 
#5
Got the frame back from the welder.
Ended up purchasing a Tecumseh 5.5hp OHV Enduro Motor from a dead pressure washer. It will end up fitting better in this frame than a harbor freight clone would -and- it ended up being much cheaper. I cleaned the carb and it works great.

Will be using a modified AC Drier Tank for it's fuel tank. Might make a hinged, fold-up seat so re-fueling won't be a problem.


Next, will be mocking up the motor and jackshaft assembly before drilling holes into the new motor plate that was welded in.
 
#6
Out with the old Kawasaki 3.?

In with the Tecumseh 5.5 Hp ohv motor

Stripped the motor of it's bulky muffler, fuel tank, and air cleaner assembly and test fitted it in it's new home.

I decided I will be routing the throttle cable through the motor where the old fuel line originally passed through, putting it right inline with the carb.

Ordered an exhaust flange and air filter adapter for the motor:
Still waiting for a few more paychecks before I can place the "big parts order" to OldMiniBikes. Probably no more updates until November. By then I should have most of the needed parts to mock up the drivetrain and exhaust before the frame gets sent out to powdercoating.
 
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6doggie3

Well-Known Member
#7
i have the same issues did this mini ever get done ?

:shrug:
Out with the old Kawasaki 3.?

In with the Tecumseh 5.5 Hp ohv motor

Stripped the motor of it's bulky muffler, fuel tank, and air cleaner assembly and test fitted it in it's new home.

I decided I will be routing the throttle cable through the motor where the old fuel line originally passed through, putting it right inline with the carb.

Ordered an exhaust flange and air filter adapter for the motor:
Still waiting for a few more paychecks before I can place the "big parts order" to OldMiniBikes. Probably no more updates until November. By then I should have most of the needed parts to mock up the drivetrain and exhaust before the frame gets sent out to powdercoating.
 
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