Restored, Refined, Reimagined: KAWASAKI GPZ900R Custom by MARVELOUS ENGINEERING
MARVELOUS ENGINEERING's GPZ900R
This machine is a recent custom work by Marvelous Engineering, a shop that mainly works on Kawasaki GPZ900R series bikes. The concept was "to pay homage to the A6 color (GPZ900R A6 stock color Black and Gold [Ebony and Pearl Cosmic Gray]), while equipping the latest specifications". Mr. Orime, the representative of Marvelous Engineering, always says, "My goal is to make customs that have me wishing they were my own bike," and like many of his customs before, this is expressed in the full paint job.
The engine was converted to a ZRX1100, the successor to the GPZ900R series, and YOSHIMURA cams were installed. This decision was made after considering the balance of cost and performance of a big bore and tuning of the older engine. Full replacement not only gives more punch and power, but also offers the reliability of a stock condition engine. Other upgrades include the latest Type-E forged aluminum wheels from GALE SPEED, Ohlins RWU forks, a WHEELIE stem and swingarm, and Brembo radial calipers/front discs. The exhaust system is Marvelous Engineering's original Conical Goldie, which was created based on years of experience, and the seat is also an original by the shop.
What is most surprising might be the background of this custom, or rather, how it came to be. It was initially brought to the store as just a stock bike that came in for the "Ninja Doc", the store's original Ninja maintenance and inspection menu. The Ninja Doc is basically a health check for the Ninja, to find out if there is anything wrong with things such as the cooling system, bearings, and chassis. Mr. Orime uses his 20-some years of experience to find any issues and get customer's Ninjas back in good shape, and many machines have been restored through this service. The Ninja Doc is so popular that there is no end to the number of reservations.
This bike underwent the Ninja Doc, and unfortunately many issues were found. After reporting these to the owner, he readily agreed to the proposed customization menu. Although this was not his original plan, customizing the bike enhanced his love for it, and since every part has been looked over by Mr. Orime, a true professional, and restoration-like work has been done, there will be no issues if further specification changes are done in the future. Although different from the originally planned Ninja Doc, this machine has indeed received a complete refresh.
Marvelous Engineering is a shop that is always thinking about the Ninja, testing things that they notice can be upgraded, and developing original parts that cannot be found anywhere else. Such parts are also used for this custom and we hope they will give some hints as to ways to soup up your own Ninja.
Handle
The stem is a WHEELIE monoblock (offset changed from 40 to 30mm) and the handlebars are low POWER BUILDER bars. The left and right master cylinders are Brembo. A PROTEC Shift Indicator and YOSHIMURA PRO-GRESS Meter were also added, and a Tagos FunKey Protect Seal is affixed to the key area.
Bodyworks
The seat is a Supreme Seat Marvelous SP, a product with the same ducktail and stock tandem belt design as the stock Ninja seat. Both the seat shape and internal urethane padding have been modified specifically for the owner.
Engine
The engine was converted to a ZRX1100 (1062cc) and set up with YOSHIMURA ST-1 cams. This engine was selected as it was in good condition and would increase power and punch at a lower cost than souping up the bike's original engine. This light modification also results in a stock equivalent life. The engine sliders are ACTIVE's hybrid type, the carburetor is an FCR φ37mm, and the under cowl is by POWER BUILDER.
Intake & Exhaust
The exhaust is a Marvelous Engineering Conical Goldie Full Titanium with a spiral collector. A GALE SPEED Elaborate rear brake master cylinder is also installed.
Chassis
The 3.50-17/6.00-17 size wheels are GALE SPEED TYPE-E from the very first lot. The front forks are Ohlins RWU (φ43mm) with Brembo monoblock calipers attached via WHEELIE supports. The brake discs are also Brembo, and ALLEGRI was chosen for the lines.
The swingarm is a WHEELIE Pentagonal Reinforced Cross Section/Height Control Swingarm with a black finish. The drive chain is by RK and the sprocket is by SUNSTAR.
The rear shock is an Ohlins piggyback type with Okamura ME tuning. The reservoir tank is stylishly mounted using Marvelous Engineering's Ohlins Tank Bracket for the GPZ900R (you can see it in the photo with the shop's logo).
The NITRO RACING steps and down tube are also suitable for the ZRX engine, and TAGOS heel protectors are installed on the lower part of the side covers.
Gallery
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Specifications
About MARVELOUS ENGINEERING
Marvelous in the engineering, without losing the likeness ninja, pursuing the only custom that left the original taste ninja.?In line with this theory, it has conducted the development of the original parts of sticking to taking advantage of the know-how.
MARVELOUS ENGINEERING brand page
Original Source of this Article
Heritage & Legends


editor
Hakuyo
A foreigner who rides in Japan, Japanese call this "Gaijin Rider". Third year in the Webike global team. He feels and shares the real bike life in Japan then presents you how interesting Japanese customs are.