1973 Suzuki GT750K Frame, Suspension, Gauges, Tin and Trim
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As yet, I've only seen one frame part number for the 1973 K series Buffalo's, which was 41100-31601-019, and which is also the same part number as is listed for the for the 1972 model J. However there are at least three different frames in use prior to the introduction of the 1974 L series, so perhaps more research will turn up additional part numbers eventually.
Early 1973 model bikes with frames built before October 1972, in the area of frame number GT750-31319, used the same 2 bolt side stand as was used for the 1972 models but this had changed to a 3 bolt side stand by frame number GT750-36493.
Although the side stand mounts differ, the rear turn signal mounts on both K model frames that I have (a 2 bolt side stand and the 3 bolt side stand) both dispense with the extended tube mounting used on the 1972 J. E1 markets had the rear turn signals bolted directly to the frame. Refer to to the Country Specific Section for the North American version.
The rear passenger pegs at least on early 1973 models, had longer bolts and doubled as exhaust pipe hangers (unlike what you see in the photo to the right !)
In the various parts listings I have available, the foot peg component is shown as being a common part to both the J and K (43511-31000), however the physical examples are obviously different. I have two different K frames (a two bolt side stand and a three bolt side stand frame), but both use the same right side foot peg mount - specifically:
The right side drivers foot peg was moved from the brake pivot post as used on the J , to a single, separate peg post attached to the lower rear frame gusset, as can be seen in the photo to the right.
The front fork ears were still painted, but were changed to have a separate mount point for the front turn signals - the front turn signal lenses were orange and the rear ones were red
The rear tail light is still a two bulb unit, and the tail light mounting bracket that holds the rear tail light, and which bolts to the rear fender is specific to 1972/1973 in that the tail light mount holes are set differently to later models (refer also to this section). There was no separate part number for the mounting bracket, as the tail light and bracket was sold as a sub-system.
Specific to the 1972, and to some early 1973 K models, is the front turn signal stalk which is drilled all the way through to fully hide the wire to the lamp, and is quite short (part number 35601-31010-999). Both North American and E1 General Export models used this for the model J, with North American models changing during K production to part number 35601-31660-999 which had a stalk roughly an inch longer.
The rear turn signal stalks had the wire coming out the side of the stalk at about the mid point, and pretty much looked the same from 1972 through to 1976, first under part number 35000-31815-999 for the 1972 model year, and then under part number 35603-31010 depending on which parts book you refer to.
The K model rear signal light lenses were red, the front ones were orange, and the round, flat reflectors which were bolted to the outside of the turn signal housings in most markets each had six facets (looks like a six slice pizza). Where fitted, for E1 General Export versions, all four signal reflectors were orange. Other countries varied - please refer to the Country Specific Section for details.
The rear shocks used the same tall upper chromed shroud as was used in 1972 suspension
The major change for 1973 was the addition of dual 296mm stainless steel disc brakes, replacing the drum brake used in 1972. The front forks share the internals of the 1972 model, but the lower fork leg is obviously different to accommodate the change to the dual front disc brakes. The bleed screw, as on the 1972 model, is mounted in the centre of the side of the lower fork leg, and the number of pleats changed during the 1973 model year from 13 to 8 pleat fork gaiters (the part number did not change: 51571-33030).
1973 was the only year metal brake line was used to connect the callipers to the middle flexible brake hose as seen in the photo to the right.
The four calliper fixing bolts (bolting the two halves of the calliper together) have knurled heads - these were used in 1973, 1974 and 1975 (59105-18410 changing to 59105-18411)
The bolts mounting the callipers on the lower fork leg were chromed (09104-10007) changing to zinc or cadmium plated bolts in 1976 which did not have knurled heads (9104-10029)
The rear wheel is pretty much unchanged through the course of the GT750 production, with the final drive gear, having 47 teeth as standard in 1973.
the E1 General Export did not use a front brake light switch, but rather had a blanking cover (57481-20010). Brake light switches were installed in some markets - see the the Country Specific section for other variations.
the master cyclinder was an aluminium casting and had an aluminium cap.
Two types of rotor were used during the GT750 production - the early type used on the K and early L's had straight sided slots which changed to fluted slots during L production. Both types are shown to the right.
The chain guard cover was black plastic (part number 61311-33000-019) - there does appear to have been a black painted metal gaurd under part number 61310-33900-019 and some very late model K's also were equipped with the chrome metal gaurd under part number 61310-33100
The inner rear fender was plastic (part number 63112-31000) and bolted to the rear chromed fender on the upper fender side under the seat using parts 4, 5, 6 and 7 per the diagram to the right. Late model K machines did have metal inner rear fenders
Both the 1972 and 1973 models used a black rubber two fuse holder for the spare fuses. This fitted onto the tab on the electrical connector panel. The same part (36790-31000) was also used on the 1973 GT185, and the 1972 through 1974 GT380 and GT550.
All markets (Japan, North America and E1 General Export) appear to have used the same handlebars, although lower bars were often fitted by dealers in Europe. The stock bar part number is 56111-31000.
The left set of handle bar switche on the E1 General Export version was specific to the 1973K having an easier to use 'up/down' high/low and on/off headlamp switch mounted above the turn signal which had pointers indicating the direction being part number 57700-31011 and having half round switch heads (57742-26010). Below the indicator switch was the horn button and below that the 'pass' or 'flash' button. Refer to the Country Specific section for other variations.
There were two styles of right side handle bar switches- the early one also used on the J having a pebbled surface on the three flat areas of the engine kill switch, the engine start button and the flat area in between and part 57100-31818. The later style has a smoother finish and is part 57100-31830.
The horn was chromed and vented in appearance.
The head lamp bucket chrome surround on early K models up until frame 37423 has a flat area on the lower edge (35100-31030) , at which point it changed to be round (35100-34030) as used till the end of production.
The rear view mirror mounts were 8 mm thread (note that the mirror anti-vibration stand-off's did not appear till 1974) and the mirrors had the Suzuki 'S' stamped into the metal backing.
The instrument cluster now used metal housings and were unique to the K model as the glass faces had a slight crown
All the gauges had black faces and were the same as used in 1972.
Both MPH and KPH indicated speedometer clocks were offered depending on the specific market.
The warning/indicator lights were from left to right on the tachometer: green for neutral (there is no LED gear indicator as was used in later models), red for high beam and orange for the flasher indication.
The under plates now had the cable opening for the tachometer and speedometer drives sentred and proportional in the plate cover, and is common for all later models (L through B)
Frame number plates varied by country, but typically was an aluminium plate having a black background, and riveted to the headstock. The frame number was stamped into the right side of the headstock.
The fuel tank was similar to the 1972 model, but used a plastic radiator fill tank flap, and had a filled tube front fuel cap hinge point.
The fill cap seen to the right initially used a push button release, but was changed in the field to have a key operated lock, supposedly for safety reasons. The early and later filler caps can be identified by the diameter of the key barrel - the early ones which were changed from the push button operation were a small diameter as seen in the lower half of the photo to the right, and the later key operated ones were larger in diameter as seen in the upper half of the photo and also actually had a keyed barrel. The small diameter caps will open with a blade.
The ignition key used a 5 digit code, and was one sided, unlike the double sided 3 digit coded keys introduced in 1974.
The seat pans are interchangeable between 1972 and 1973, and very nearly interchangeable for all years. There was no seat lock - a thumb latch was used - so early pans to be used on a later model need to be modified in the area of the seat lock. Later pans to be used on a 1972 or 1973 ideally need to be filled in where the seat lock cut out is located. The seat covers in 1972 and 1973 had a distinctive
diamond pattern as seen to the right, with a one piece polished stainless steel surround trim (with no seat lock gap) and 'Suzuki GT' was silk screened on the back.
The rear brake plate did not have the wear indicator casting by the rear brake arm, but rather was smooth.
While the rear wheel was largely unchanged through the course of the GT750 production, the final drive gear did change in later years. 47 teeth was standard in 1973. As well the rear shocks varied model to model, and the original shocks in 1973 were the 'high hat' style.
The front forks are 35mm in diameter (as are all the GT750 front forks) and the 1972 and 1973 models share the same fork tubes and both used rubber fork gaiters. The 1972 J model as well as at least some of the earlier 1973 K models used 12 or 13 pleat gaiters (depending on how you count them) shown to the right. At some point in 1973 they changed to be 8 pleat gaiters shown on the left side of the
photo, and which are still available from Suzuki. Oddly, there is only one part number shown in the Suzuki parts catalogues (51571-33030), so perhaps there were two different suppliers ?
Also note that the fork oil drain screw is centrally located on the outer side of each lower fork leg.
The front axle was shared with the 1973 K model having a hex headed collar that the left fork left clamped on. The fixed end of the axle end is in shown in the upper photo to the right, and the two types of removable nut used for the J and K models and also for the L and later models are shown in the lower photo to the right..
