Totally Forked

I have been saving a new pair of Suzuki GT750 J/K style fork tubes (or stanchions if you prefer) for many years in anticipation of using them on a restoration, and the time finally had arrived. When I first looked at the old ones on the current project that I refer to as ‘Big Blue’ (see more on my web site at this link)  the chrome in the areas that the seal contact actually looked quite good and there was no pitting to speak of that I could see. This is obviously a credit to the rubber fork boots that had slightly survived all those years of sitting outside in all weathers. However, upon closer inspection, I discovered that one tube was slightly bent. While it could be straightened I decided to take advantage of the fact I had replacements and got to work. After all, replacing fork tubes is a simple job so how long could it take ? Quite a while as it turned out ….

I bought these tubes from CruzinImage in Japan via eBay, and while most of the time I’m really happy with both the quality and the value of their products, this was one of those instances where it didn’t quite hit the mark.  As a matter of interest, I note that CruzinImage hasn’t offered fork tubes for the J/K for quite some time which probably should have been a clue. There is a lower piston or valve that has to slide over the bottom of the tube (part number 51112-31030) and I found that the tube was just fractionally too big in diameter. As the tube is chromed, and as chromium plating is hard, my options were either to grind the surface of the tube down, or hone the inside diameter of the valve to make it bigger. My toy lathe has a very small through hole in the head stock, so I removed the tail stock and set the tube up using a steady rest with one end held in a chuck to see whether or not it would run true enough that I could use an oil stone to grind down the chromium plating. The reason for doing so is that replacement pistons/valves are hard to find, and so I didn’t really want to modify any good ones that I had. In the end, it worked well enough. And then I ran into another problem.

As the tube was ever so slightly too big, the circlip that the piston/valve butts up against prevented the valve from moving far enough up the tube to allow it to fully seat home. As a result, I found that the lower snap ring that secures the piston/valve would not seat into its groove. I seriously considered going back to the old tubes at this point, but then decided to go ahead and shave just a hair off the inside step of the piston/valve. Once this was done, it all fit together as intended.

My plan is to keep the old tubes and at some point I may look at trying to straighten them. In other places on the globe you can get tubes re-chromed and then ground back to the original size, but here in Canada there are not a lot of options. I do have the name of a place in Toronto, but the cost appears to be more than buying a new set from a place like Frank’s Fork (previously called Forking by Frank) in the USA or from Tarozzi in Italy. I have previously bought fork tubes from Frank’s and the fit was exact and the price was reasonable, so if I were to do this over again, that would be my first option.

And so the build continues !

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Updates and Additions

I have been lounging in a warmer place than Southern Ontario this past couple of weeks (in Southern California to be exact !).  In between carrying parcels as SWMBO’d shopped, acting as a tour guide to my daughter-in-law who was able to join us both here, and also entertaining my in-laws Judy and John, I have also managed to do a few updates and additions to the OJB web site. Some will already have seen the additional manuals that I added four weeks ago. Those included the addition of the :

And the:

As well, this week I have added the :

And the:

Just ‘click’ on the links above to take a look. I suspect that will pretty much complete the manual selection that I plan to offer. I’m still missing the T20 Parts and Owner manuals, as well as the T200 manuals but I’m good with that and if they fell into my lap, then I could eventually add them I suppose. My interest is really just road machines and so I hesitate to expand the offering to include models used off road, or indeed to road models offered outside of Canada. That could always change in the future I guess.

I still get requests from people to send them PDF’s of the material I have posted. As mentioned on my Manuals page I don’t do that. Excellent quality hard copy manuals are easy to buy at very reasonable rates from e-Classic Bike in New Zealand, or from Amazon and eBay etc. I know there are people who painstakingly copy down each of the images I post and then offer them around to people as PDF’s. They are low resolution images to make them load faster and often I’ve water marked them, but really if that’s what you want to do then have at it I suppose. Whatever turns your crank. And keep in mind that I have not designed these to be viewed on a phone. Having an old laptop or large tablet in the work shop is a cheap accessory, and it is what I’ve done for years. I encourage others to do the same.

In addition, I was also able to add a Japanese Domestic Market dealer manual that Drew Courtney in the UK lent me. This is quite interesting to page through as it shows models not offered elsewhere, along with dealer specific material such as retail prices in Yen for the different models. Having that material prompted me to update the section on the web site slightly and split the sale brochures area into JDM and ROW (for ‘rest of world’) sections which I can continue to add to as material comes available. You can view this new addition at this link.

Details of my latest restoration ( another 1972 GT750 ) are slowly starting to be added at this link on the web site . I expect it will be a slower build than others I’ve done in the past as it is taking me a while to track down suppliers offering the same quality of service in Ontario as I had access to in Calgary. I know they are out there – I just still need to do the due diligence and satisfy myself that I can get what I want at a price I’m prepared to pay.

And I also figured out the answer to a question about water pump seals that I’d been curious about. If you’ve wondered where to buy a replacement mechanical seal for your GT750 or for your RE5, then I wrote about that at this link , and now have also added the seal information to the web site here.

I’ve also added a small write up on making your own engine stand that Skid Brown in the UK has graciously allowed me to share here. This first appeared in the Kettle Club’s newsletter and you can read about it at this link .

Finally, I have started something completely different ! In response to a fellow who asked why I didn’t actually have much on the site about “really” old Japanese bikes, I have started to remedy that omission. I have started putting together a compendium of sorts which covers other JDM machines prior to roughly 1960. I very deliberately am not including much material on products from the ‘Big Four’ manufacturers as there is already loads of material available. For this project, I wanted to shine the light on the manufacturers that no longer remain. It is very much a ‘work in progress’ but you can take a look at what little I have done so far at this link.

That’s all for the moment. As always I continue to make other small changes and updates here and there – too many to list really. The errors and omissions are all mine and I very much do appreciate people letting me know if they find something that needs to be corrected.

The fun continues !

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Big Blue In Progress

Elsewhere in OJB land, I have been working on my next 1972 GT750 restoration. This one will be blue and like the previous red one I did a couple of years ago it is in really rough shape. However, it is the next consecutive frame number to the red one and I like the idea of former assembly line mates being returned to their former glory. Currently I have completely disassembled it, and the engine cases, block and head are away for vapour blasting at Wolf Worx Motorcycle here in London, Ontario. Before taking the block there I had Can-Am Machine remove one of the studs using spark erosion (EDM). Although I had been able to raise the block slightly, one stud had jammed/seized and try as I might, I could not get it to budge. I was able to remove the block from the cases after cutting the offending stud with a hacksaw blade and so rather than risk damaging the block, I decided to get some help. They did a really nice job.

I degreased the frame and checked to see if it was square using some string and a tape measure and generally it looked quite good, however the rear turn signal mounts were badly bent. After a few sessions with some heat and gently straightening the mounts, I was happy with the final result. For testing I am using a set of scrap signals with the long stalks just to check for true, but the ones I’ll be using on the final build will be quite a bit shorter. These welded stubs were only used by Suzuki for the early frames and then replaced by bolt on brackets in North America. Elsewhere in the world the signals threaded into shorter stubs right on the frame.

Next on the list is to tidy the frame up here and there before sending it out for powder coating. At this point, I’m still checking to see who I’ll use, but I’m sure I’ll be able to find someone local to the London Ontario area to do the work at a reasonable cost.

Internally the engine looks almost new ! There are almost no marks on the clutch basket fingers at all, and the gears in the transmission look pristine. There are some signs of spun bearings on the cases, but that is easy to fix with a bit of Loctite 638.

Externally though there are a few problems, one of which is that the block itself suffered a close encounter of the hard kind  on the left water jacket and has been repaired at some point. The repair weld was filled with Bondo and doesn’t look great, although I think I may be able to draw file the area to clean it up enough that it will look OK. If not, then I’ll have to consider my options. Of course, when you consider it is 47 years old I suppose a few battle scars are not something to be ashamed of.

The cylinder bores still show the cross hatch marks from the original hone and there is no sign of pitting so I think I may just buy some new rings, give the bores a quick hone and call it a day.

All in all – good progress !

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Kwakification and Drums

I know this will make my friend Wade happy, but the Kwakification of my Suzy’s continues ! I had always been curious where places like DiscountBikeSpares in the UK or GTReiner in Germany were sourcing the mechanical seals for the GT750 water pumps. Obviously someone was making them, and while these places provide excellent service I decided to do a bit of research. Terry at Wolf Worx here in London let me take a look through a couple of his supplier catalogues and one of them (MC Distributing) listed a whole page of after market mechanical water pump seals. With that information in hand and after asking the question on a couple of boards, it turned out that a suitable seal to fit the Suzuki GT750 seal is used in several Kawasaki’s, as well as some Chinese models. As with the oil injector valves (see my previous post at this link) the Kawasaki mechanical seal with part 49063-1055 is a direct fit and the cost is reasonable so I’m happy to buy them locally. As a matter of interest, it is also made by the same supplier (NSO) who made them originally for Suzuki.  Inglis Cycle here in London were able to get the Kawasaki part in for me at a cost of slightly under $26 CDN (taxes in). Note that the part comes with a new seal face (seen below the Kawasaki part on the left side in the photo above) that is not used on the Suzuki water pump, so you do still have to refresh the metal seal face that Suzuki uses (replace it, lap it or skim it on a lathe) in order to ensure a good seal. Note also that this mechanical seal also fits the RE5 water pump and was listed under Suzuki part number 17470-31010.

Via places like eBay, you can buy cheap Chinese knock-offs of this Kawasaki seal for as little as a $1 USD ! I bought a few different ones just to see how they compared with the Kawasaki one. The one in the photo to the right cost me about $14 USD, but on close examination does not look very well made. I think it would probably work OK, but not in one of my restorations, as I prefer to only repair them once if possible. As with the Kawasaki part, it comes with a seal face which you discard as well as an oil seal that is the wrong size for the Suzuki GT750.

DiscountBikeSpares in the UK sells the mechanical seal for about $47 CDN which seemed a bit high to me so I didn’t buy one from them. Reiner in Germany sells them for about $31 CDN (a bit more than that if you also live in the EU as VAT is added) which is close to the local cost here in Canada. The seals that Reiner sells appear to be repackaged Kawasaki parts, or at least are from the same OEM supplier as they are also made by NSO and are of very good quality. I’ve used the mechanical seals from Reiner previously and I’ve never had any issues. Both Reiner and DiscountBikeSpares use the Suzuki part number 17470-31010 if you go searching for them.

So when all is said an done, I find that I now have more than enough mechanical seals on hand; likely more than I’ll ever need I suppose. On the other hand it is nice to have another small mystery solved, which I hope will help anyone else who wishes to rebuild their own water pumps !

Changing gears a bit – there is a thread on the UK Kettle Clinic board (one of the better publicly accessible ones available if you want Suzuki GT two stroke assistance) about the differences between front drum brakes. Specifically front drum brakes as used on the 1972 GT750 and GT550 J models. The part numbers for both the GT750 and GT550 front drum brakes are the same, however there appears to have been two different versions of the front drum with earlier frame numbers below about 12400 on the GT750 having a narrower front drum assembly and so requiring spacers. Later frame numbers used a different part number for the drum assembly which was wider and so did not require the spacers. Purely out of curiosity I was wondering roughly when the change happened, and so I’ve put out requests to owners having low number frames on several boards and forums. If anyone reading this has a GT750 or GT550 with a frame number below about 12400 I’d like to hear from you as to whether you have spacers installed. To make it interesting (well – at least slightly more interesting I suppose…  🙂 ) I am running a small contest which you can read about on my OJB Facebook page at this link.

And so the fun continues !

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1972 Suzuki GT750 Gauge Shells – Update

After six long years, I am finally down to my last twenty sets of GT750J reproduction gauge shells and about fifty reproduction speedometer reset knobs. It has been a journey, but I have no regrets.

Recall that I started this project in 2012 when I picked up my first Suzuki 1972 J model and started taking a look at what options were available to repair the cracked plastic housings on the gauges. Suzuki only used these plastic shells for the 1971 Japanese Domestic Market and 1972 General Export model years, and they are often broken. Repairs are possible if the crack has not extended up into the clear plastic lens, but if the lens is also cracked then you have a real problem.  The idea of having the gauge shell reproduced came about following discussions with my friend Allan Tucker from Barbados. We looked at a few different reproduction options, none of which proved viable. I then started the process of reverse engineering the original design and had some duplicates created using 3D printing which at the time was useful as a ‘proof of concept’ but useless as a finished product. The issue was the clear plastic lens. The 3D printing materials and processes available at the time could not produce a clear plastic lens with the right optical characteristics suitable for a restoration. I suspect the same is still true today. While the test blanks were of no use as replacements, they did confirm the design and provided me with a sample that I could then show to injection moulding companies.

In the end, I went ahead by myself to finance and organise the manufacture of the shells, and as I first documented (at this link) a company in Edmonton worked with me to create what I think is an excellent product.

When I first looked at having these shells reproduced I tried to guess how large a market there was. The original GT750 production numbers would indicate that about 20,000 of this model were originally sold worldwide. Hagerty Insurance in the US published an interesting chart giving survival rates of motorcycles by manufacturer which showed that about 45% of all Suzuki’s were still in use after 25 years. Extrapolate this out to 46 years and the number of survivors starts to look quite small – certainly less than 10%, so for 1972 model year GT750’s specifically perhaps as many as 2000 machines. While the numbers for a specific model like the GT750 will differ from a those of a Suzuki moped, I note that the sole GT750 registry I know of, which is maintained by Martin K. in Germany, only shows about 420 GT750 J’s in total. If you then consider that not every gauge shell is cracked, and that some people are happy to use later model gauges rather than the originals, then it becomes clear that the total available market for this product is quite small indeed. I do still own the injection dies, and now that the cost of creating the dies has finally been recovered, a second production run of tachometer and speedometer shells would be much less costly to produce. At the moment though, I am not planning on having more of these shells made as I suspect the available market is near saturation. At the rate of current sales, what stock I have left should last about one more year (so mid to end of 2019) and then perhaps I will re-evaluate my decision.

And of course there is still the problem of the temperature gauge shell as I only had the tachometer and speedometer shells copied. I didn’t do it initially as the temperature gauges are often not damaged, and as well due to the manufacturing costs of the injection die they would have to sell for about the same cost as the larger tachometer and speedometer shells do currently. Cost is definitely an issue for some owners, but it would be a nice addition for restorers. Possibly a future project for someone else perhaps !

For the three 1972 GT750’s of my own, I now have fully refurbished gauge sets so the original problem that started me down this road six years ago has been addressed. And roughly 180 other GT750 J owners’ world wide have also benefited, so I’d call that a success !


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Just Tooling Around

I like to have a complete, as per original, tool kit for my restored bikes. While it is possibly true that the original factory tools were not the best quality or the most useful, in my view no restoration is complete without this final touch. While many of the Suzuki factory original tools are fairly easy to find, for the GT750 specifically there are a few specific tools which are increasingly hard to source. Examples would include the contact points tool (09930-20111), the open end 8 mm wrench (09813-00025) which also served as the T handle for the cross head driver and finally the small  10mm box wrench, or spanner which is part number 09816-00001. A photo of the original tools is near here – just ‘click’ to see a larger version. The 10mm box wrench was included in tool kits fitted to the 1972 through 1974 GT750’s plus earlier bikes like the B100P etc., and necessity being the mother of invention, I decided to make a few.

I have two uncles who know a thing or two about making things out of metal, so after getting a few suggestions from Don specifically, I sourced some seamless tube in various wall thickness’s from a company called Aircraft Spruce Canada and did some experimenting. You need to use seamless tubing for this process, as welded tube will split when you try to form the tubing over your mandrel. 

The photo to the right taken by a friend of mine in Calgary by the name of Art, shows what an https://oldjapanesebikes.comoriginal 09816-00001 tool looks like and its approximate size. It measures roughly 1 3/4 inches long and is about 1/2 inch in diameter. What I wasn’t sure of was the wall thickness so to cover my bases, I ordered a couple of different wall thickness’s and also two different OD measure tubes so I had a selection to try. I had never tried doing this before, and so after several attempts using different methods (heated or cold) and also trying the various different sizes of tubing I had to work with, I had a nice selection of scrap as can be seen in the second photo.

The successful solution was to slowly press a thicker walled tube over the mandrel I’d made with the tubing cold but generously lubed with a cutting oil. Some time ago a friend in Calgary (John) gave me a 20 ton press that he no longer needed which makes this quite easy. To finish it off took only a few minutes on the drill press and then a bit of time to dress the edges.

The finished product can be seen to the right below and I am quite pleased with the result. I now just need to get them zinc plated along with the rest of the tools and Ill be good to go !

On to the next challenge !

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(Almost) The End Game

It has been a good week ! I started the engine on the current project for the first time, and although there were no mosquitoes to be slain, there was enough smoke generated to have done the job if there had been any. 🙂

The engine sounds healthy and I’m hoping that the remaining small jobs can be completed quickly so I can get the bike in for an inspection and then on the road. That last part is a bit up in the air, as there is still a lot of snow about, and of course still quite a few weeks of potentially wintry weather still to be had, but there is at least a light at the end of the tunnel.

Just to recap, this is what the bike looked like when it first arrived (just click on the images to see larger versions):

And this is how the bike looks now:

The gauges will not be back from Allan Tucker till sometime later this summer, so for the moment I have temporarily mounted a spare set from a later model machine. I still have a few things to tidy up – the exhaust pipes refuse to seal properly for example, and I also need to finish the fuel tank installation – but I’m pleased with how it looks and sounds.

Now we just need for all the white stuff to be gone !

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Wrangling GT Switch Gear

Time to get the switch gear sorted, and of course nothing is straight forward. The 1972 model GT750 used a one year only set of switches, and good working examples are difficult to locate. As well, internally the left side switch is quite different from later models as it has individual block switch modules for each function.

I actually just had one left switch for the GT750 and a second left switch that was from either a T500 or a T350 of the same year as it was unpainted aluminium. The GT750 switch gear was originally painted in gloss black. This unknown left switch also had the connector block cut off and so needed new wiring and black plastic sleeving, but otherwise looked complete. As can be seen in the lower part of the photo (just click to see a larger version) . it was also wired differently from the GT750 version seen toward the top of the photo, having different colour codes and termination points on the headlamp switch modules internally.

Disassembly of these switches is not for the faint of heart as there are a lot of really small components inside them: small springs, even smaller steel balls, little brass slider contacts and little tiny screws which seem to disappear as if by magic into the darkest deepest recesses of your work area, never to be seen again ! My first step then, was to clean the the switch blocks with electrical contact spray cleaner without attempting to disassemble the individual component parts, temporarily reconnect nine-pin connector blocks and then check with an ohm meter to see whether they worked at all.  A couple of the switches did not work at all on the silver left switch and so then needed careful total disassembly to properly clean them. During reassembly I lubed the interior contacts with dielectric grease, and also did so for the modules I didn’t disassemble.

When wired up temporarily to the bike, and with the power on, they now all worked reliably with the exception of the horn button on the ‘real’ original GT750 switch. A closer examination showed that the circuit board was cracked, and so when pressing the horn button, the flexing of the board caused intermittent contact. This early switch was also a different design than later ones and is actually missing the lower metal clamp that provides support for the board to keep it from flexing. You can see the early switch (left) and a later one (right) in the photo to the left. I’m not sure when the change was made, but it would have been after frame 16153. The left switch was completely redesigned for 1973 and later models using a round housing similar in shape to that already used on the right side, and the headlamp on/off and high/low beam switch was simplified. The combination horn and turn signal module however used in the newer left switches was the same up until sometime in 1974. Luckily I had a later style scrap left switch and so was able to salvage a working horn/signal switch module.

The internals for the right switch gear are pretty much unchanged through the course of GT750 production.

With the switch modules sorted out, I then stripped the switch cases down for painting. When SWMBO’d was out shopping, I cured the painted cases in our counter top toaster oven for an hour. 🙂 Once they had cooled down, I added the orange paint (I use Testors Tangerine 1126TT) for the lettering using the ‘dab and wipe’ method  and re-installed the internals, using new black sleeving and connector blocks that I buy from Vintage Connections in the USA.

The final result looks pretty good, and also works which is always a bonus ! On to the final finishing steps as I get closer to seeing whether the engine will fire up ! And If you are interested in all the different switch gear used during the GT750 production, they are covered in ‘The Field Guide to the GT750’ which you can find at this link.

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Getting Pumped !

Oil pumps, and more specifically Suzuki oil injector pumps, have been occupying a good deal of my attention recently. For an in depth understanding of what they are and how they work, I suggest you take a look at the excellent overview of Suzuki GT750 injector pumps written by a friend of mine, Richard Nowson, which can be read at this link. The design of these for the Suzuki GT750 is quite robust, but they are also 40+ years old now, and like all things mechanical (and otherwise I suppose !) are starting to show their age. I needed a working pump for my current project (which is documented here), and so I dug into my ‘box of bits’ to see what I could come up with.

The oil injector pump on a two stroke is obviously a critical engine component and if the pump fails you risk having a solid block of scrap metal in fairly short order ! It is possible to run pre-mix, but due to the design of the crankshaft bearings, doing so is not recommended. Before trusting your engine to a pump with no known history, as a minimum it makes sense to bench test it and I wrote about one way to do that some years ago at this link. Since then, I have made a bench top tester from a scrap crankcase I had. The kickstart shaft on the Suzuki GT750 also drives the oil pump, so a friend of mine turned down the end of the shaft on his lathe so I could mount a pulley and then drive the assembly from a fractional horse electric motor. I’ve attached a video of it in operation below:

I really should fit a guard as the HS&E folks I used to work with would likely have a fit, but it does the job.

If you listen to the sound of the pump, you can hear the change in tone as the pump lever is pulled forward. Below is a photo (just ‘click’ to see a larger image) of the underside of the top cap showing the rod that is being rotated. The slot in the middle rides against a pin on the top of the rotating piston. As the shaft rotates, the slot allows the piston to increase its stroke and so pumps more oil. It is important to note that the pump always pumps at least some oil – backing off the pump arm adjustment will only decrease oil flow at higher throttle openings, so if your engine smokes a lot at idle then backing off the adjustment doesn’t actually do anything. Over time, what can happen is that the top of the rotating piston will wear, and/or the shaft will wear, and should this happen the pump stroke increases and more oil is pumped – a sort of built in fail safe design I suppose.

Note: when reassembling the cap, it is possible to reinstall the shaft 180 degrees out of phase so that the pump will run at full output volume at engine idle. Make sure that the slot in the shaft faces away from the bleed screw and toward the pin as shown in the photo. Also note that later style pumps do not have the pin.

Often when pulling the rotating piston out of the barrel, you forget to hold the pump upside down, and so all the springs and pins fall out of the rotating piston ! Early pumps have three pins/plungers and later ones have only two. Should this happen to you, don’t panic – the springs are all the same and the short plunger fits the bore having the draw hole nearest the driven end of the pump shaft, as shown in the photo to the left.

The third plunger in the early pumps actually is used to draw oil from the injector tank and was found to be unnecessary and removed. I don’t recommend mixing and matching pump parts as there are a number of design differences.
For example the rotating piston in the early type having the third plunger also has a restricted inlet at the top of the rotating piston. Richard goes into much more detail about the different pump designs in his write-up.

There is an oil seal in the underside of the pump body which is still available from Suzuki (part 09285-08002). The rest of the pump was not intended to be user repairable, but as is often the case necessity is the mother of invention.  New top gaskets are available from several places – I buy mine from Reiner in Germany as the exchange rate for the Canadian dollar usually favours the Euro, but Ian Beardsley in the UK (check this link) also sells them and the quality is excellent. The same gasket is also used on pumps fitting the GT550 and the GT380.

One item that so far at least I have not been able to source is the small u-cup oil seal used on the actuator shaft. When this seal fails, injector oil starts to leak out the end of the shaft at the top of the oil pump. This seal is an odd size, and while I have managed to find some that are close, the fit isn’t ideal. I’d be happier if there was more contact area between the seal and the shaft bore. The replacements do seem to work, but I only have about 8 hours of run time on one and so am not yet confident of how long they will last. I’ve attached a photo here showing a replacement seal installed on the shaft  – as you can see it is the correct ID and OD, but is really too narrow for the slot in the shaft, so I plan to keep looking for something closer to the right size.

The bottom line is that after a couple of days of sorting, testing, rebuilding I now have a couple of injector pumps I’m happy with ! I’ve put the test pump with the replacement oil seals to one side for the moment and will circle back to run it for a few more hours on the test rig before I actually try it on an engine.

The build is getting close to being complete – just fiddly things like the handlebar switch gear to be done, and then perhaps I can make some smoke in a week or two – maybe. 🙂


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Hooters, Guards and Etc.’s

The chain guard (or chain case if you prefer) on the 1972 and 1973 model GT750 is plastic, and you often find that the mount points are damaged. Over time the two special ‘top hat’ washers typically go missing, and just using an ordinary flat washer compresses and then eventually fractures the plastic, making it a scrap item. As these original plastic guards are becoming hard to find, it makes sense to use the correct fittings, especially as they are still available from your friendly neighbourhood Suzuki dealer under part number 09169-06010. Locally here in Calgary, I deal with GW Cycle World which is a family owned business who have been very helpful to me over the years. Recommended.

The horn on these is the early louvred style, having a chrome plated cover which is held in place by five aluminium rivets. As is often the case, the horn I wanted to use was not actually working, but luckily they are fairly easy to repair. I’ll post more detail on my web site at this link, but basically so long as the coil is good you can usually bring these back to life by cleaning the contacts, and then by adjusting both the points gap and the distance that the solenoid (hammer) is pulled into the coil before it hits the anvil . The anvil is threaded in from the back of the horn, and moving this in or out will change the pitch of the horn, although admittedly the sweet spot is quite small. What you do not want is for the solenoid/hammer to be set so it can’t move to open the contacts, as that risks burning out the coil. The adjustment is the small cross head screw on the back, and I use an ohm meter to ensure I am starting with an open circuit before applying power and trying to make adjustments. On this one, I had the louvred cover re-chromed, reattached the cover using stainless steel screws, re-sleeved the wires and it is good to go !

Suzuki changed over to having an AMP connector block to join the front and rear main wire harness together sometime after the 1975 model year I think. This was a great improvement on the earlier style of connectors which had a tendency to overheat and melt the connector jacket, and then potentially short out under your fuel tank. Not an ideal situation ! The harness I planned to refurbish for this project was the later type, and as part of that process I had to get the AMP connector apart. The AMP connector is a bit fiddly in that to release the pins or sockets  from the plastic holders for cleaning etc., you need to compress in the two retainer tangs located on each side of the pin or socket that lock it into the plastic holder. You can see one of these tangs in the photo to the right. A similar pin extractor as used on the 3.5 mm flat blade crimp fittings will work which can either be bought or made.

Next on the list is the switch gear !

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