HotrodMiniBike Custom Azusa 3545 Drag Bike Build

Hot Rod Mini Bike Build

For this project we used a basic frame and fork assembly manufactured by Azusa engineering . Azusa has been in the Go Kart and Mini Bike business since 1960. The frame is manufactured and welded here in the USA. It has a very cool retro style Mini Bike look, but has it’s short comings when it comes to tires, rims, brakes and controls available from the manufacturer to build it. Our goal was to upgrade all the components and take this to another level capable of handling one of our built competition level 212 Ducar racing engines.

Azusa 3545 frame and fork set.

First of all we noticed there is no steering head stop on the Azusa frame which will cause the fork cross bars to carve into the frame tubes damaging any paint work we would do.
So we fixed this by fabricating up a steering stop to protect our new powder coating job.
We removed existing flimsy rear axle mounts and drum brake anchor from frame. Then
lengthen the wheelbase by adding custom fabricated rear gussets to frame tubes with 12 mm axle mounts.
This will allow us to use 10 inch pit bike wheels with a sport/street tread tires.
We custom made a center stand.
Fabricated and welded in fuel tank mount tabs to top frame tubes.
A front mount to use a MCP billet brake caliper was fabricated and a mount anchor tab for the fork tube.
Also rear brake caliper mount and anchor tab for rear brake system.
We added fender mounts for our custom Carbon fiber Fenders
And rear wheelie bar mount tabs.
A foot peg cross bar was added. This supplied some extra rigidity to the front frame tubes
and a solid peg mount instead of the flimsy Azusa clamp on peg system.
Frame/Powder Coating
 3 Stage powder coating with clear coat.
Color- #FF2800 Ferrari Red
And last we fabricated a Chrome Molly Wheelie Bar
Engine build time!
 The Ducar 212 was chosen due to its added block strength and reliability.
Modifications and additions.
Block modifications for governor and oil sensor removal.
 High compression flat top piston.
Milled and ported 14 cc head, 36 lb Valve springs, stainless steel valves, alloy spring retainers with automotive style keepers.
Chrome molly push rods
Head stud kit
.275 lift camshaft with 1.3 roller rocker arms. =.357 cam lift.
PVL alloy high RPM flywheel .
ARC billet connecting rod.
Crankshaft mods for high lift cam clearance.
24mm Mikuni flat slide carburetor.
HRM slide carburetor manifold.
HRM top plate.
Custom made HRM header.
Dyno tuned @ 17.27 hp @ 7038 rpm. Test performed on our in house Land and Sea water brake Dyno system.
Valve clearance .003
Oil  Briggs/Amsoil 4T racing oil   16-18 oz
Fuel 90+ octane ethanol free Gasoline
10 inch Chrome pit bike wheels with upgraded with sealed high speed bearings.
Tires- 130/60-10 Sport Street Tread.
MCP Billet Hydraulic calipers
DOT braided stainless steel brake lines
Custom 8mm banjo fittings.
Compact Pocket bike style L and R master cylinders.
Drive system.
HRM/PMR  billet engine mounted Jack Shaft System
Sprocket combo 10/25T Gear ratio 7.7 to 1
Noram 12T GE Ultimate Clutch with 3400rpm Springs (green) Clutch shoes set at setting #5
#35 EK Silver primary drive chain
#420 EK rear drive chain
HRM Aluminium clutch and chain cover
Final assembly and test ride!
As with any Mini Bike sporting this level of engine build….This thing hauls a#*!   It demands respect and throttle control.
But most of all it stops!!! Something that is usually lacking with these bikes. With a brake system that has now been taken into the 21st century there is no wimpy scrub or drum brake action here!
No Fred Flintstones shoe dragging required to slow this one down. The brake feedback is awesome from the MCP calipers. Nice feel at the levers. No grab or fade.
Just good aggressive brakes as any Hot Rod should have it!  This custom build is ready to go to it’s new owner in Idaho. A blast to build. We are certainly going to miss it!

6 thoughts on “ HotrodMiniBike Custom Azusa 3545 Drag Bike Build

  1. Tom Mott says:

    Awesome build, sure would like to see you guys come up with a wheelie bar for the old school doodle bug db30s that’s all pro tricked out like this AZUSA drag mini? No doubt I’d buy one!

    • hotrodminibike says:

      Thank you for your comments! Wheelie bars are for sure on the list to do. Check back in the future as we should have something available.

        • hotrodminibike says:

          The rims are easy to source online. 10″ disc brake Pit bike wheels. Tires are 10 Street Tread Scooter tires. The frame on the bike was modified to use the 14mm axles used on the Pit bike as well. Reducer’s welded in the fork legs and rear axle mounts fabricated and relocated in the rear.

  2. Scott says:

    Incredible Build. Raw Talent.
    Just built my 2nd Azusa Mini Bike. Few more Mods to complete but they are never done.
    Thanks Guys

  3. Mimi Brusa says:

    Wow, this hot rod bike was really cool to read about. I would love to see the bike in action in a YouTube video. A wheelie bar added would make this bike. People can’t get enough of cool re-makes. Makes me think of my childhood where we were always working on go karts and souping them up and racing them. I’ll check back here again for sure.

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