A perfect harmony of aesthetics and engineering

After serving 8 years in the Navy, Derek Kimes was scouting for new challenges. But little did he know that a day would come where he would custom build and custom engineer a motorcycle that would go on to win top honors at the Forged Invitational show at the Jekyll Island.

It wasn’t any other motorcycle, but his own 1982 black Yamaha XJ750 Maxim re-engineered to replicate the 1984 XJ750R (0U28) race bike that participated over in Japan in the 1984 Suzuka 8 Hours, both in terms of design and performance. This modern machine gets retrofitted with fuel injection and ...wait for it… a freakin turbo kit.

It’s aptly called the Yamaha “Turbo Maximus” spooling 200 hp.

Yamaha “Turbo Maximus” Exterior
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Built with the help of his colleagues at Fuller Moto, a custom shop run by Brian Fuller, the Turbo Maximus is an exercise “not only from a fabrication standpoint but from an engineering approach as well.” And who would believe that this is Derek’s first ever custom build?

Thriving to replicate OEM quality and standards, Derek has shown quality fit and finish. Starting with the installation of the 2003 Suzuki GSX-R 600 throttle bodies carb-FI kit successfully unlike many who have tried and failed. Miles of wiring and harness is neatly tucked hidden from any eyes going all across the MS3 PRO ECU, EGT sensors, CAN BUS to an AIM MXS dash.

Yamaha “Turbo Maximus” Exterior
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Yamaha “Turbo Maximus” Exterior
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Yamaha “Turbo Maximus” Exterior
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Yamaha “Turbo Maximus” Exterior
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The engine was totally swapped with its bigger brother’s 1983 XJ900 900cc mill and has been fully rebuilt by renowned NASCAR engine builder Jordan Hersey of Atlanta. Multiple modifications on this takes the power rating all the way up to 200 hp. It includes 9:1 custom forged pistons from JE Pistons, FZ750 camshafts, titanium race valve springs, Custom Lockout clutch, Moroso remote oil filter, stainless fuel filters, custom aluminum intake air box and more.

The most challenging aspect was the turbo kit that needed to be assembled as tight and integrated into the bike as possible. Derek says “I wanted it to look like the bike was designed originally to be turbocharged.” He opted for the Borg-Warner S1BG that was big enough to spool the massive 200 hp he needed and at the same time, small enough to tuck in between the frame and front wheel. (He hated the idea of having either the turbo hanging way out and or the charge tube is wrapped around the engine).

Yamaha “Turbo Maximus” Exterior
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Yamaha “Turbo Maximus” Exterior
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Yamaha “Turbo Maximus” Exterior
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Yamaha “Turbo Maximus” Exterior
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The goosebumpy aural orgy is courtesy of the Turbosmart supersonic blow-off valve making a great PSHH! along with the titanium Akrapovič slip-on muffler getting its inputs from the custom 3-into-2-into-1 stainless steel headers and exhaust pipes.

A custom fabricated Bell intercooler did the cooling duties and was located right above the turbo. This created another set of problems as there wasn’t any space for the oil cooler. After scratching his head for multiple days, Derek finally got it right by routing the oil lines underneath the bike to the rear where he relocated the EARL’S 25 row oil cooler just in front of the rear wheel.

Yamaha “Turbo Maximus” Exterior
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His love for the XJ series grew on since he owned his first motorcycle that he bought in 2005 as a used. With the ’84 XJ750R (0U28) race bike in his sights, he began fabricating the bodywork, especially the custom one-off aluminum tail section and Swing-arm. At the front, Derek got the F1 replica fairings custom made by Airtech-Streamlining and added a bespoke headlight bezel handmade from aluminum which carries a JW.Speaker LED unit.

A custom made windscreen by Gustafsson Plastics completes the race bike feel to it. The fuel tank has also been swapped with another Yamaha, a 1977 Yamaha XS750 this time. A Dual Fuel cap fabricated by RaceFit keeps things clean. The retro rear brake and integrated turn signal lights come from The Retrofit Source.

Yamaha “Turbo Maximus” Exterior
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The frame was modded and straightened for precise alignment and was powder coated. The bike even replicates the white-red-blue paintjob from the ’84 XJ750R with the engine painted in satin black and wheels in white. Rubber is from Metzeler Racetec RR K2 compound having the rear wheel borrowed from an XJ900S with an FZ1 rear caliper and FZR 1000 brake rotor. CRG race clutch and brake controls made from billet aluminum have a precise feel. The foot controls sees Suzuki GSX-R 600 sets.

The rear dual shocks were swapped with an adjustable piggyback monoshock unit. At the front, the stock unit was replaced with a 2015 Yamaha R6 Front Suspension with Traxxion Dynamics AK-20 Cartridges complimented with the Ohlins steering dampers.

Yamaha “Turbo Maximus” Exterior
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Quite honestly, I can keep going on with hankering all my lust with this build onto this article, but Derek here has built a gem of a machine. Beautifully crafted bodywork and a well-engineered powertrain combine with such awesomeness, I wish they had more high-def images for me to change wallpapers.

Bike Exif says- “To call ‘Turbo Maximus’ a restomod would be selling it short. It’s a re-engineered masterpiece, and one of the few occasions where mechanical brilliance is matched by a keen eye for aesthetics.”


Source: Silverpistonphotography and Bike Exif

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