Some of the best stories have the most humble and unexpected beginnings. Little did Zane, Adam and Jake English of ZAJ Customs know, but when they swapped a carton of beer for two CB750 engines, it would turn into a 3-year saga of trial and error. Based out of their workshop in Margaret River, Western Australia, this is their homage to Honda’s mighty CR750.
Adam runs Margaret River Motorcycles, the famous coastal town’s local bike shop. When he’s not fixing and servicing customer bikes, he’s wrenching on his own with his two sons, Zane and Jake. After finishing an XS650 hardtail chop project, the family were looking to dive into another project. This is when the CB750 engines surfaced on a local Facebook page.
After retrieving the engines and returning them to the workshop, Adam tracked down a local CB750 guru. This guy had thousands of CB750 parts and this is where Adam got the frame, steering stem, forks and triple clamps.
“I like building customs with my sons,” explains Adam. “It gets us into the workshop together and bikes are fun to muck around with.”
Starting with the wheels, Jake began by machining some factory hubs. After this, they were off to Brian at Spoke Wheel Services for him to work his magic on. They returned with stainless steel spokes, laced to fresh Excel rims.
The factory forks were rebuilt with progressive springs and gold valve emulators and they were converted from single to double-disc. The front brakes were treated to Goodridge stainless steel braided lines and a fancy Brembo radial master cylinder. The drum brakes at the rear also got some love – it was converted to a cable-operated setup (which took weeks of work for Adam) and a custom vent was cut into the drum cover.
A replica CR750 fibreglass fairing was ordered from Airtech Streamlining in the USA, along with mounting brackets. The Airtech mounting brackets weren’t as substantial as the boys would’ve liked so Adam decided to remake them himself. Adam originally wanted to cut a headlight into the fairing but he was outvoted by the two boys. Admittedly, it looks way better without the headlight.
The alloy fuel tank and fibreglass tail section came from Good Bits in the UK and once the team were happy with the fitment, they were sent off to paint. Andy King at Margaret River Panel and Paint took care of this, laying down the beautiful candy red paint and custom decals.
Tarozzi clip-on handlebars were slid onto the forks, with Zane making the dashboard by hand. Dominated by a large tachometer with an offset speedo, the intricate work makes it one of our favourite parts of the build.
The engine was rebuilt with mostly stock parts. That’s not a bad thing, considering the original factory CR750 engines were notoriously unreliable. However, a full brace of Keihin CR Roundslide carburettors were installed and jetted to suit. Fitted with K&N filters and combined with the stunning black 4-into-4 exhaust system, this gives the old CB750 engine a nice performance boost. An oil cooler from a Suzuki GS was fitted to the front of the frame, with custom oil lines running along the frame to the alloy oil tank. An oil temperature gauge was added to the engine, thanks to Motorcycle YAMIYA in Japan who also supplied the exhaust and brake caliper brackets.
For maximum reliability, the bike was completely rewired. This is Adam’s favourite part of the bike, as he was able to sit at his kitchen bench and make it all from scratch – yes, he has a very understanding and tolerant wife. The custom loom is completely concealed, with the majority of the electronics located under the seat and the custom battery box hidden under the swingarm.
Speaking of the swingarm, it’s from a later-model CB750F1 and it is suspended by new adjustable Icon shocks. Just like the race bike, Zane and Jake trimmed and looped the rear subframe and Jake recessed the tail light into the seat hump. Together with the tiny Motogadget indicators, the back end is still road-legal, thanks to the removable number plate bracket. There are countless brackets and braces that the boys made over the years, including the rearset footpegs that Zane made.
Besides ripping it up and down their street, Jake was the lucky guy to take the CR on its first proper shakedown ride. He took it through the Boranup Forest, just south of the workshop, before Adam took it on a multi-day ride through the lower southwest region.
“It rides really well,” says Adam. “It’s quite smooth, which surprised me for an old bike.”