The GT750 was produced from 1971 (GT750J) to 1977 (GT750B) after being shown to the public for the first time at the Tokyo motor show in 1970.
The GT750 was unique. Not only was the engine a 2-stroke three cylinder, it was a 750 (actual size was 738-cc) and it was water cooled.
Combined with direct oil injection, the Suzuki was a sophisticated motorcycle in its day. However, in the middle 70s, motorcycle emissions were coming under greater control in most countries, and the GT Suzuki was considered to be one of the worst (most polluting) vehicles on the road at the time.
The water cooling system drew much attention from the worlds press at the bike's launch, quickly attracting aquatic nicknames such as: water bottle in Australia, water buffalo in the US, and kettle in the UK.
The bike proved to be a reasonable seller for Suzuki after some initial fears of the new engine configuration. Although the water cooling made the engine more efficient and quiet, buyers were concerned the water system would be vulnerable on a street bike.
Besides water cooling, the new Suzuki featured some tried and tested technology, such as direct injection oiling, alongside new ideas such as the balanced exhaust configuration. This new system was known as the Exhaust Coupler Tube System (ECTS).
Unique Exhaust System
This system was unique in having two cylinders with individual pipes and mufflers and one cylinder (the center cylinder) having a split system of a single header pipe splitting into two smaller mufflers. In addition, the three down-pipes were linked with a tube which gave rise to the name ECTS.
The exhaust system was primarily designed this way for packaging reasons; having a split center configuration gave a balanced weight distribution for the entire exhaust system. However, many of these engines were eventually used in racing (both in sidecars and solo's) where the stock exhausts would be replaced with three expansion chambers which greatly reduced the overall weight and improved out-and-out performance considerably.
The carburation on the early versions was by way of three Mikuni carburetors. As with all multi-carburated motorcycles, keeping the carbs in balance was very important for smooth riding, acceleration and fuel economy. However, the original slide type carbs were replaced on the K model with 40mm Mikuni CV (constant velocity) types.
Front brake on the first model (the GT750J) was of the twin-leading shoe design with an internal diameter of 200 mm, but these were changed to twin rotors on the K model. Besides becoming popular for street bikes in the 70s, the twin rotor set-up was necessary to slow the not inconsiderable weight (507 lb's. dry) of the GT750.
During its production run, the GT750 received a number of cosmetic changes and the power output gradually increased from 67 hp on the first (J) model to 70 hp on the last (B).
With the success of Suzuki's GS range of sports bikes, the GT750 was discontinued in 1977, however the water cooled three cylinder 2-stroke has a strong following with classic bike collectors and riders alike.
2011 prices for a perfect example of the B model are around $4500.