Kawasaki’s two-stroke triples were some of the company’s greatest bikes of all time. The legendary H2 750’s earned their “Widow Maker” nickname and were the fastest production bikes in the world upon their release. The H2C was the final version of the model and the so called “Purple People Eater” livery is reportedly the rarest of the H2’s factory color schemes. This beautiful ’75 H2C’s restoration has had a ridiculous amount of time and money dumped into it and the results are pretty outstanding.
In the mid-to-late 1960’s, Japan’s major manufacturers were churning out increasingly impressive models like Honda’s CB450, Big Red’s first “big bike”. Kawasaki sought to take a piece of the large-bore market and a secret mission to deliver a new ground breaking motorcycle from the ground up was created under the corporate code-name “N100 Plan”. At the time, America was the largest market for these types of machines and Kawi’s new model aimed to lock down a good chunk of that market with a half-liter bike that made at least 60 hp and could do a standing-start quarter-mile in no-less-than 13-seconds.
Kawasaki’s engineers tackled the task in two separate fashions – boring out their proven A7 “Avenger” 350cc two-stroke, parallel-twin, rotary-disk engine to 500cc’s while simultaneously taking what they’d learned and using it to develop a brand new three-cylinder two-stroke layout that would eventually become the air-cooled two-stroke “L-Triple”. To address the cooling issues the new L-Triple was having, Kawa’s people called in some help from Osaka University’s Faculty of Engineering’s laboratory and staff to perform tests to help dial in the right cylinder pitch and cooling fin length for optimal heat displacement.
After more than two years of development being kept on the down low, Team Green pulled the cover off the H1 Mach III in 1969. The new model was tremendously successful and Kawasaki would take the know-how gained from the development of the H1 to deliver a handful of other models such as the Mach II S2 350 in ’71, the S1 Mach I in ’72, and the H2 Mach IV 750. Though directly derived from the H1’s 500cc power-plant, the H2’s triple had been engineered to produce significantly more low-end torque, and the Mach IV sported a chain oiler, steering damper, and an all-new capacitor discharge ignition system.
At the heart of the H2 – or Mach IV – was an air-cooled, oil-injected 748cc three-cylinder transverse two-stroke engine married to a chain-driven transmission with a five-speed gearbox. The three-quarter liter three pot reportedly made 71 to 74 hp at 6,800rpm – depending on the model year – and 57 ft-lbs of torque at 6,500 rpm. The engine was wrapped in a double tubular steel-cradle frame that was damped by inner-spring telescopic forks up front and three-position adjustable tube-shocks in back. The standard brakes consisted of a single disk in front and a drum unit in the rear, though a second unit up front was an optional add-on. And with a power to weight ratio of one horse power for every 5.7 lbs, and a dry weight of 423 lbs, that second brake was a good idea.
Changes were made to the Mach IV in 1973 when adjustments were made to the carb jets, cylinder port timing, and oil-injection pump in an attempt to get better gas mileage. Interestingly, the fastest and most powerful H2’s were the models from the first year or so of production. The H2’s that followed were still by all means plenty powerful, but the earliest examples have a couple extra ponies over the later models like the H2A, H2B, and H2C variants – starting with 74hp when first produced but going down to 71 by the time production ended.
In 1974, the engine was modified on the machine – that would be designated the H2B – in an effort to tame the beast a little and make the bike more “civilized” and easy to manage, a feat that would cost the scoot some of its oomph and resulting in three fewer HP. The oil-injection system on the ’74 H2 now had two different sets of injection lines instead of one, and oil was injected into the three 30mm Mikuni carbs on a separate line with tubes running to each carb. The three separate lines running to the bottom-end bearings were kept from the previous year, but a longer swing-arm was added to give the two-wheeled rocket better stability, though the bike was also more planted thanks to its extra 36 lbs, giving the final H2C model a total weight of 459 lbs. Other tweaks for the ’74 model year included a trimmed-down tail section as well as a different steering damper and a few other minor changes.
The H2 models were, and continue to be some of the most gorgeous motorcycles ever made. They wonderfully embody the spirit of 1970’s design and their two-tone paint-jobs, asymmetrical three-barrel exhausts, and sporty naked looks all combined with a powerplant that was nothing short of a feat of engineering all add up to make one of the most iconic classic motorcycles ever. Obviously, its performance played a much more substantial role in the model’s place in the moto-history-books, but the Mach IV’s appearance definitely didn’t hurt. Among its innovative qualities, many point to the H2 as the first sport bike to use its pronounced tail-section as a storage space, a trait that just about every modern super bike utilizes today.
This particular 1975 H2C model has undergone an extensive restoration and though it does stray away from using all original components, the modifications made definitely boost the bike’s performance and seemingly weren’t done in an effort to cut corners or save money. The Kawa was stripped down to the chassis and every component and inch of the bike have been meticulously combed through. All of the “main components” were built by hand by Paul Gast of New York’s Fast by Gast – a shop that does service and produces performance parts for two and four-stroke Kawa’s, though it started by specializing in Kawasaki’s triples.
Paul Gast tore down the engine and rebuilt it with a new crank, seals and gaskets, and bead-blasted cases. He’s also responsible for the new chrome plating on the outer cases and custom Fast by Gast expansion chambers. Next, he broke down the transmission before rebuilding it with all new parts. The stock Mikuni carbs have been replaced by a trio of new Lectron FBG 36 mm P3 flatside carbs (including the $200 Lectron tuning rig). Gast also did all of the top end work that included replacing the pistons and rings.
On top of Paul Gast’s work, this Mach IV’s restoration included a new complete electronic ignition system from Lakeland Services that features an all in one CDI, super regulator, and low speed coil upgrade. The instrumentation on this example was redone by Don Fulsang Gauges, and every fastener has been individually addressed with most of them replaced or re-zinc’d. The price tag on this example isn’t cheap, but considering the current seller says they have receipts for all the parts and services from the restoration – which add up to more than $12K! – the price seems fair, especially when you account for the price of the bike itself (which was reportedly another $12K).
This example appears to be in pretty remarkable, albeit unoriginal shape but is still worth a lot. Previous Bonhams auctions reveal that the going rate for these 1970’s Kawasakis are in the ballpark of what the seller is asking. Last year a 1975 H2 was valued at one of the prestigious auction houses events for between $14 and $18K, and back in 2011 a restored 1975 H2C sold at a Bonhams auction for just shy of $15K. In addition to the thorough record keeping the current owner has done, they’ve also thrown together a video of this exact bike being started up and ridden around a little bit, as well as a slideshow video of some photos of the restoration.
You can find this restored 1975 Kawasaki H2C 750 Mach IV for sale here on Craigslist in Las Vegas, Nevada with a price of $17,500.