Several Suzuki enthusiasts around the globe have written handy guides and useful reference sheets, and I've gathered a few together here. As with any such resource, this information is provided as information only, and I accept no responsibility for injury to you, your friends, or to your machine. You are responsible for doing your own due diligence and research as to the appropriateness of the information for your situation and requirements.
In most cases, just 'click' on the link to open, or you can right click and then select 'Save link as'. And if you have something that you would like to contribute, just drop me a line !
- Carburettor Linkage Repair
- Gearing Chart
- Steering Stem Bearings, HT Leads and Brakes
- Ignition Leads
- Water Pumps
- Baffle Removal
- Exhaust Pipe Rebuild
- Oil Pump Shaft Seal
- GT750 Engine Stand
- Gauge Repair
Carburettor Linkage Repairs
From Tim Harwood in the UK :
a common failure point is the linkage connecting the carburettor shaft to the oil injection pump actuator rod - depending on where you live, this is either a rose or a helm joint and the part that fails normally is the plastic olive or ball in the centre You can click here to download Tim's 'how to' sheet to repair the fitting - Tim can supply the parts as a kit on request, or you can put your own kit together
note that Reiner Schneider in Germany offers the plastic olive under his part number 16762-31210-000-Z
Also - there is Allan Tucker's low budget method if the swivel fitting is in good shape - 1 #10-32 nylon hex nut, 2 #8 stainless steel finishing washers - total cost in USD of $1.48 to make your own olive/rose joint/helm joint. Click here for a photo of the final result !
From Richard Nowson in the USA:
- a useful gearing chart for the GT750 showing ratios and RPM or MPH
Steering Stem Bearings, HT Leads and Brakes
From Keith Rudd in the UK:
a useful guide on fitting tapered steering head bearings - a common issue is that the shoulder on the steering stem is too high and must be cut back, and Keith walks through the process.
- and here is a data sheet from All Balls bearing company concerning the same modification to the steering stem
- how to replace the high tension leads on the coils - this process is applicable to many Suzuki's of the early 1970's
* a series of articles on master cylinder, calliper and rear brake service and while written for the GT750, the general instructions apply to most early 1970's Suzuki - please note that if you have any doubts at all, or have never done this sort of service work before - get help. A botched brake repair could prove to be fatal not just to you, but also to anyone you run into.
Allan Tucker in Barbados came up with this clever method for removing the water pump from the GT750. Basically if the water pump is stuck and you have to get it out, and if you don't want to pull the engine and strip it down, it is possible to pull the starter motor, drill a small hole in the upper crankcase and then (with the bottom cover plate, impeller and retaining circlips removed of course) tap out the water pump using a suitable drift. The measurements to find the location to drill the hole are shown here, and the finished 6mmX1.00 threaded hole and stainless steel grub screw can be seen here. Further details are available at this link. It works, but be aware that if your measurements are off by even a little bit you will have ruined your crankcase and you will still not have your water pump out. You have been warned !
Harry Davies in the USA sent along his method and photos of the tool he made for removing the water pump on his engine which are on this page.
- Tore Greganberg in Norway has written up a good step by step 'how to' guide for rebuilding your water pump.
- The oil seal and top bearing are available from any commercial supply place and the o-rings are available from Suzuki.
- The mechanical seal is available from Kawasaki under their part number 49063-1055. It is also available from places like eBay, but the quality varies a lot so buyer beware. You can read about the seal in more detail at this link.
- Allan's excellent description of how to make a cylinder block puller for the GT750 are shown on this page.
- Gunnar has listed several alternate methods to remove the cylinders at this link
- Some additional photos of another puller made by John Wilson here in Calgary.
- Suzuki's solution is described in US service bulletin GT25
There are several tricks you can try for removing the baffles on Suzuki, or indeed any make of two stroke exhaust. The baffles often are glued in with coke, carbon and rust in those cases where the bike has sat un-used for decades.The most important point is to go slowly.
Looking at Suzuki triples specifically, something to be aware of is that the interior bulk head plates inside the pipes are only spot welded to the inboard side of the pipe. The outboard side is just pressed against the outer exhaust skin. As a result, if an internal header has been bent or damaged in some way by a previous owner, removal of the baffle will be very difficult as the damaged plate will jam the baffle. Cutting the pipe open and then re-welding it may be your only option.
In those instances where you are pretty sure the problem is just coke and/or carbon then:
- liberal application of your favourite solvent (diesel, commercial brands of penetrating oil, varsol, kerosene/paraffin) is what I normally try and to date has worked for me nearly 100% of the time.
- soaking the pipe in a caustic soda solution may help for very gummed up pipes - just be sure to take all the appropriate safety precautions as severe injury is possible if you are not careful. Also, in this day and age safe and legal disposal of the solution will be an issue in most countries.
- Glenn Reay is a fan of bumping the end of the pipe on a block of soft wood. While this will work in many cases, it works best on pipes that have recently been in service.
- and finally, Tim Louth in the UK came up with a novel method using a wallpaper removal steamer which worked well for him. Note that the pipe will be hot so suitable gloves and personal protection will be needed to prevent injury. He says he steamed the pipes for about 45 minutes and the baffles then slid out easily
Oil Pump Shaft Seal
Ian Judd in the UK is one of several folks who have come up with a solution for leaking shaft seals on the injector pump. These use a 'u' seal from the factory which seems to be completely unavailable and so other types of seals including o-rings have been tried, generally with poor success. Ian uses an 'x' ring seal and has produced a very good write up explaining what he did. You can download it from here.
I regularly am asked about how to repair GT750 clocks/gauges, as well as the clocks/gauges of other models. I have done basic repairs on my own clocks on my daily riders, but for restorations I have generally farmed this work out to someone who I trust to do a proper job. Clock restorers of course are reluctant to share any of their secrets, and deservedly so. They are trying to make a living at it after all, but sometimes the bike doesn't warrant spending a load of coin on the clocks and so doing the work yourself may be an option.
First of all - clocks are very easy to ruin. If you do opt to try repairing your own, then you really are on your own, I accept no responsibility if something goes wrong, and typically you will not get any sympathy from whomever you go to if you need someone to bail you out of an unfortunate error. You have been warned. I do list a few clock/gauge restorers at this link and if you have any doubts at all, then I suggest you select one of them before trying it yourself.
For the 1972 GT750 J model, I had reproduction shells made to replace the cracked plastic ones you normally are faced with on this model. I may have more of the plastic shells made, but I am currently (in 2019) sold out although I do still have a few reset knobs available. I have provided a very high level 'how to' repair guide to just replace the plastic shell which is located at this link. I don't go into detail about adding damper fluid to the dampening pot as this is easily done wrong resulting in a scrapped guage, however for those brave enough to give it a try I have included a couple of photos below showing where those pots are located - tachometer on the left and speedometer on the right below.
The rubber lamp sockets in the base of the speedometer and tachometer perish with age, or sometimes the socket wiring is defective and you need to do a repair. At first glance, the wires seem to be sealed into the sockets as a part of the mould, but in fact they just have a dab of rubber cement to seal for weather. This can be removed (see first photo below) and in the photo I show using a set of pull wires to pull in a replacement socket. If the rubber boot on your gauge/clock is too far gone, then at the time of writing you could order them from Marcel at this link. Excellent quality and service, and also very reasonable prices, and shown in the second photo below.
And finally, the later (1973 through 1977) clocks/gauges had the upper metal shell held in place with a crimped stainless steel ring. This has to carefuly be removed if you hope to re-use it again, which is not hard to do, but hard to do well. For both the removal and the reassembly you need to hold the clock in some way and some people use a large hose clamp (called a jubilee clamp in some countries), but Bjorn in Scandenavia has a neater solution as shown in the photos below. With the gauge securely clamped in place, a small dull ended screw driver can be used to safely prise off the ring, and the same clamping assembly can be used when re-installing it. If you have ruined your old ring, these are also available from Marcel at at this link at the time of writing. For greater ease of re-installing the ring, if you notch the ring (make it look saw toothed) first, you will make life easier on yourself.
Good luck !