Keeping the Dream Alive: Jacko’s All-Motor Magnum…
In the history of motorcycling, the United Kingdom is famed not just for its legendary marques but its small-batch chassis builders as well. Certain names are spoken with reverence both there and abroad: Rickman, Spondon, and Harris Performance, to name a few. Brothers Steve and Lester Harris started the company more than 50 years ago, and their frames, machines, and teams would go on to excel at nearly every level of road racing, from the Isle of Man to British and World Superbike to Grand Prix.
Today, Harris Performance is part of Royal Enfield, and the Hertford-based workshops have been instrumental in the design of modern Enfield production machines. However, if you grew up during the age of the big air-cooled four-cylinder superbikes — and the custom streetfighter craze that followed in their wake — Harris is legendary for one thing above all others: the Harris Magnum, a series of tubular frame kits designed to house those monster engines.
Originally derived from the Harris endurance racer campaigned by Mike Trimby and Marty Lund at the World Endurance Championship, the Magnum wrapped those +1000cc Japanese engines in a gorgeous high-tensile steel tube frame whose geometry and design was far superior to the OEM standard of the day…and the bodywork was to die for, too.
Our new buddy John “Jacko” Jackson has long regarded the Harris Magnum with proper awe, ever since the 1990s when he loved all the custom-frame streetfighters of the day but couldn’t afford one. Today, Jacko has three good mates who all own a Harris, and the passing of another good friend inspired him to take the step toward Magnum ownership himself.
“A close friend of mine ‘Hank’ lost his life on a Harris. Harrises were his / my holy grail bikes and I needed one to keep the dream alive and honour his passing.”
We can think of no better reason to own one of these legendary specials, and some of the UK’s most highly regarded tuners have laid hands on the Magnum you see here. Though the frame had a number of previous owners, this iteration of the machine began when Tom Davidson of the UK’s Havoc Paint got hold of the Magnum II frame and one-off Spondon swingarm to build a special to promote his bike-painting business.
This particularly frame was intended for a Suzuki GSX1100 EFE engine, which Tom brought to none other than Dave Dunlop of Fast By Me Turbo Systems, one of the most revered names in high-performance motorcycle engines. However, forced induction was not the plan for this EFE mill. No, this was to be an all-motor monster, boasting a 1428cc MTC drag block and MTC high-comp pistons.
Roger Upperton — a legendary UK Suzuki tuner — gas-flowed and modified the head, aiming for streetable midrange power from the big-block engine:
“The gas flowed head is +2mm inlet, standard exhaust. 2mm Base spacer has lowered the CR from 13.5:1 to about 11.5:1 the theory being to produce a reliable mid-range grunt but giving the starter motor a chance of actually spinning it.”
Dave at Fast By Me assembled the engine, and Tom at Havoc Paint did most of the design, base work, and of course laid down the gorgeous paint that harks back to the wildly colorful streetfighters of the 90s.
Our man Jacko bought the project, did a dry build, and then his good buddy Toddy (“the best bike builder I know”) spent about a year wiring, fettling, and finishing off the bike so “it could be ridden hard and ridden anywhere.”
The bike rolls on Ducati 999 wheels, and Jacko’s buddy Kev “Banga” Bancroft rebuilt and modified the Suzuki GSX-R K4 forks while of FTR Suspension tuned the WP rear shock to suit the build. The tank is one-off, fabricated by Scotland’s The Tank Shop, and the tail section is a Zed Butt unit.
Aptly nicknamed “Touch Too Much,” this is one of the maddest specials we’ve seen. Jacko has yet to have the 1.4-liter air-cooled beast on a dyno — the motor just finished being run in — but his 300-mile shakedown run in Wales was a treat. Not only does the bike “handle like a dream,” but he found it’s “more comfy than it looks.” But the best part has to be that big-block propulsion:
“No idea on power but it’s not slow!!!! It’s got the old-school grunt…”
Not only is this one of the baddest, most gorgeous Magnums we’ve ever seen, it’s one hell of a tribute to Jacko’s lost friend Hank, and a testament to the dreams we keep alive on two wheels. Below is our full in-depth interview with Jacko about the build, including many finer details of the project and a full tech spec. Key the AC/DC and enjoy a “Touch Too Much.”
GSX1428 Magnum II: Owner Interview
• Please tell us a bit about yourself, your history with motorcycles, and your workshop.
John “Jacko” Jackson, 50 years old, born in the UK and live in Australia (but always hanging out in the UK in my spare time 😉). I’ve been riding and working on motorcycles forever. Always dreamt of owning a Harris. I have three really good mates who own and ride them, and I needed one badly, so when this one came up for sale with its 90’s looks and big motor I jumped on it!!!
Also, a close friend of mine “Hank” lost his life on a Harris. Harrises were his / my holy grail bikes and I needed one to keep the dream alive and honour his passing.
• What’s the make, model, and year of the donor bike?
Harris Magnum 2 frame, 2001, built for a Suzuki GSX1100 EFE motor.
Most of the parts do not belong with this bike 😊 It’s almost all a one-off.
• Why was this bike built?
From what I understand the bike (frame and Spondon swingarm) had a few owners in the UK and had gone through a few iterations. Tom from Havoc Paint got hold of it and began building it in his vision.
The main work done by Tom was paint and overall design. Tom took an EFE engine to Dave Dunlop at FBM Turbo systems to build with a 1428 MTC drag block and MTC high comp pistons.
Roger Upperton, a bit of a legend in the world of Suzuki race engines, gas flowed and modified the cylinder head. The gas flowed head is +2mm inlet, standard exhaust. 2mm Base spacer has lowered the CR from 13.5:1 to about 11.5:1 the theory being to produce a reliable mid-range grunt but giving the starter motor a chance of actually spinning it.
Dave from FBM Turbo systems assembled the motor.
Tom repainted the frame for me before I bought it and did the dry build, and then my good mate “Toddy” spent about a year (on and off) finishing and refining it so it could be ridden hard and ridden anywhere.
• What was the design concept and what influenced the build?
Tom built it to showcase his bike-painting business and just because he’s big fan of big old-school air-cooled Suzukis. I like it cuz it’s a nod to the 90’s streetfighters (when I loved the bikes but couldn’t really afford one) and it’s something that looks good with my Simpson Bandit helmet 😊.
There are now four of us really good mates with Harrises (a Mag 1, 2x Mag 2’s and a Mag 4!), which is a dream come true really.
• What custom work was done to the bike?
Everything!!!
- 1428 GSX1100 EFE engine by FBM and Roger Upperton
- GSXR K4 forks rebuilt and modified by Kev
- One-off Spondon GIA Swingarm
- White Power shock rebuilt by FTR Suspension
- Ducati 999 wheels
- HEL radial calipers and master cylinders
- One-off tank by the Tank Shop
- List goes on!!!
• Does the bike have a nickname?
“Touch Too Much.” Because it is, both in how it looks and the size of the motor and carbs 😊, and I like the song 😊
• Any idea of horsepower, weight, and/or performance numbers?
Will get it on the dyno in 2025 — no idea on power but it’s not slow!!!! It’s got the old-school grunt.
We have just re-torqued the head and serviced after the initial 400 mile motor break in. We realised the clutch was fried so fitted a new SPS HD Clutch and HD springs, a new HD starter motor as well as the old one burnt out trying to spin the 1428 over 😊
• Can you tell us what it’s like to ride this bike?
Amazing, with the modern rubber and rebuilt suspension it handles like a dream. Big shoutout to @ftr_suspension and my mate Kev “Banga” Bancroft for his work on the forks. I get to ride lots of bikes and this one really does ride well!!!! I think the Harris frames must have been well ahead of their time.
We did a 300-mile shake down ride this summer in Wales from England and it’s awesome!!!! It’s more comfy than it looks.
• Was there anything done during this build that you are particularly proud of?
Toddy getting over the finishing line and ready to ride.
• Is there anyone you’d like to thank?
- Toddy for the quality of the final build, the wiring loom, and being the best bike builder I know.
- Kev “Banga” Bancroft for the engineering work and front forks mods and rebuild.
- Tom for letting it be my turn next to own it and having the vision to build something so wild.
- Suzuki Performance Spares and Grumpy 1260 for all the trick bits.
- FTR Suspension
- FBM Turbo Systems
- Roger Upperton Racing
- Andy “Ho-Show” Hawkins for showing me at a young age what a trick motorcycle should actually look like!
- The Mrs for letting me spend the money 😊
Build Sheet
Motor
- Suzuki GSX1100 EFE
- MTC 1428 big block
- MTC high comp pistons
- Upperton Racing cylinder head gas flowed
- Kibblewhite stainless oversized valves, heavy duty springs and titanium retainers
- RS 40mm Mikuni flatsides with Ramair filters or velocity stacks
- Vance & Hines exhaust
- Mocal oil cooler with Grumpy 1260 frame and head feed
- Grumpy 1260 front sprocket cover
- SPS oil filter cover
- SPS billet clutch arm
- APE racing rocker bolts
- APE racing manual cam chain tensioner
- APR racing heavy duty head studs
- SPS ignition cover
- SPS engine breather
- Ricks HD starter motor
- SPS Powerscreen HD clutch plates and springs
Electrical
- Dyna Coils
- Dyna S ignition
- Taylor leads
- One off wiring loom by Toddy
Chassis
- Harris Magnum 2 frame 2001 build for EFE motor
- GSXR K4 forks rebuilt and modified by KBR Racing
- Renthal fat bars
- One-off Spondon GIA Swingarm
- White power shock rebuilt by FTR Suspension
- Ducati 999 wheels
- HEL radial calipers and master cylinders
- Brembo rear caliper and HEL master cylinder
Miscellaneous
- One-off tank fabricated by The Tank Shop, Dumfries
- Engine assembly by Dave Dunlop at FBM turbo systems
- Zed Butt seat with Triumph tail light
- K4 front mudguard
- Paint work, design, and dry build by Havoc Paint
- Wiring, final build, and preparation by Toddy, my good mate
I love it!!!
What a thing.
Death machines
Excellent m’boy Captain Mayonnaise would be proud!