Powder Prep

I’ve been spending a few days preparing several items for the Calgary CVMG club ‘powder coating day’ this coming Saturday.  Should be interesting as I haven’t actually seen this done before – other than on television of course ! I hope to have two motorcycle frames ready to go – both are Suzuki’s, one being a 1973 GT750 and the other being a 1977 GT500. I’ve spent the past few days disassembling and getting them stripped down, taken lots of photos and bagged and tagged many of the smaller bits and pieces, nuts and bolts.

Today I spent some time washing off the accumulated dirt and  oil from 30+ years of use.  I had briefly thought of  doing this in my driveway using my pressure washer, but very quickly rejected the idea as it would flush small amounts of oil and grease down the storm drain. Instead, I took everything over to a local Shell car wash as they (supposedly) are set up to keep this sort of debris out of the storm water system.

I’ve touched on Shell’s marketing folks and what an odd lot they are previously. Some time ago (before I retired !) I had suggested to the same brilliant marketing folks at Shell that keep closing filling stations so you can’t find one when you need one, that they start to consider the value of putting Shell’s name on the roofs of our buildings. When you consider the number of people using the various free mapping services offering satellite photos that show tons of detail, you would think it would be a no-brainer. A few companies have actually done this in the USA, and Microsoft offers this capability in a virtual fashion with Tim  Horton’s coffee shops and Petro-Canada filling stations in some parts of Canada using their Bing mapping service. In the photo to the right, you can see the Shell station and car wash I used – or at least you can now that I’ve pinned a label on it with an arrow !  Imagine how it would look with a big Shell pecten on the roof – this of course hasn’t happened. As I may have mentioned previously, our marketing folks border on genius in much the same way that hammers do – not very much at all actually, but I digress ……

The parts are now all freshly washed, and tomorrow I go over to the good folks at Consolidated Compressor here in Calgary to sand blast all the bits and pieces. I wrote about them previously here , and this time I will be using their indoor glass bead blasting cabinet for the smaller items and the outside sand blasting stations for the two frames. I have to admit, for someone like myself who doesn’t have to do this sort of thing for a living, there is a certain fascination about watching the old paint, rust and anything else that happens to get in the way and isn’t firmly attached get blasted into oblivion – it promises to be fun ! If all goes well, I’ll have Friday to blow out any bits of grit and make sure everything is ready to go for the main powder coating event Saturday morning.

I’ll let you know how it goes !

1973 GT750 Rebuild – Rethink

More problems – so making a few changes to the project plan.

Once I had the Calgary donor bike stripped down, I was able to put its frame along side the Kincardine frame and then noticed a few differences. Earlier GT750 frames in 1972 had a 2 bolt hole side stand and in late 1972 for the 1973 model year, this was changed to a 3 bolt side stand mount. For some reason, the Kincardine frame was the earlier 2 bolt hole style, and the side stand itself was not original and would need to be replaced. As well, on closer inspection I found that the Kincardine frame had a broken engine mount. The engine and frame for the Calgary bake were original and so the serial numbers very nearly matched (Suzuki frame and engine serial numbers seldom match exactly, and can actually differ by a wide margin). As they were original and close, it seemed a shame to give that up. The frame was cracked in the rear fender stay – not really a key structural member and so could easily be welded. The centre and side stands were both in very good shape. The engine was another story entirely. The Kincardine frame of course had no engine, and so would have been a ‘bitsa’ bike anyway – given a choice then of building a ‘bitsa’ or doing a restoration, I decided to restore the Calgary frame and engine. Of course nothing is ever easy …..

Whenever the Calgary bike had been parked – sometime back in the 1980’s – the oil was allowed to drain out and then it had sat outside in the snow and rain for the next 25 years or so. The barrels came off easily using the puller, but the sight that met my eyes once I cracked open the side cover wasn’t pretty.

There was a lot of rust – my guess is that the engine probably had been in good condition when parked, but over the years had gradually become seized solid with corrosion. Basically other than the cases, barrels, cylinder head and side covers there wasn’t much else I could really use – luckily I have several sets of transmission clusters, and crankshaft assembles so I can replace all the internals with parts from other engines. This does cause a bit of a potential problem though, as the number of teeth on some of the drive and intermediate gears changed over the model years, and I’m not sure which model year cluster sets I have on hand. As well, I will have to mix and ,match the gear sets a bit to minimise the lash in the drive train. Normally there are paint codes on the inside of the engine case, and sometimes on the gear clusters also to assist with lash adjustment, but for some reason this engine had no paint codes inside at all. The water pump, not surprisingly, is shot but I can either rebuild it or replace it. More work than I had expected, but all very doable.

Today I took in a GT750 crankshaft to Greg’s Cycle here in Calgary to have new seals installed. Assuming that nothing much else is wrong with it, I expect It should be ready in about 2 to 3 weeks.  I still need to check the barrels to see whether I need to use over-sized pistons, or just re-use standard size ones, but that can wait till after the crankshaft is finished, and I have the gear clusters, crankshaft and all the other bits and pieces back in the cases.

The next few weeks then will be busy getting the above items sorted, plus I have another item I need to prepare for also. Our club is having a ‘powder-coat’ day here in Calgary in early September which I’d really like to take advantage of. This is made possible by a local supplier and basically you show up with your items prepped and ready to go, and take them home freshly powder coated for very reasonable rates. With a bit of luck I hope to have both a GT750 and GT500 frame ready to go, together with all the bits and pieces (battery box, side and centre stands, swing arm etc.).

Of course that means I’ll need to strip down the 1977 GT500, which I haven’t really even looked at yet.

The Puller

Getting the barrels off of the GT750 engine can sometimes be damn near impossible. What happens is the cylinder head studs corrode, especially the locator studs, and the barrels become firmly stuck. In the past I’ve pulled the cylinder head nuts and then filled the bolts holes with 3-in1 or PB Blaster penetrant from Canadian Tire, left them to soak for a few days or a week and then been able to eventually wrestle the barrels off.

Suzuki actually recognised that getting the barrels off was a problem quite early in the production of the GT750, and made a change to the cylinder head bolt washers (service bulletin GT-5 of May 1, 1975) to try and address the corrosion issues, and also made available a puller (service bulletin GT-25 of August 15, 1975). Both of these service bulletins, and all the others, are available here and here.  The problem with the Suzuki puller, is that if the barrels are REALLY stuck, then you risk stripping the threads you have to cut in the barrels per their procedure and then you are totally stuffed !

An alternative is as per the photo to the right which was made by John in the local Calgary Water Buffalo group. Basically its a flat steel plate drilled out in the same pattern as the cylinder head. The plate is bolted the top of the barrels and then threaded rod is run through nuts welded to the plate, down into the cylinder bolt holes till they seat on the studs. Then, if all goes well, you just walk the barrels off by progressively tightening the threaded rod which pushes against the tops of the studs and lifts the barrels up and off.

This is a view showing the barrels pulled up part of the way – you can see the degree of corrosion on the studs which meant they really did not want to let go ! In a case such as this, a puller is almost mandatory.

I was just tearing this specific engine down for parts – it is one of two that was included in the 1973 Suzuki GT750 basket case that I picked up in Kincardine, Ontario. While the barrels, crank and pistons were all scrap (lots of severe damage, and signs of seizure), there was a brand new (or at least virtually unused) nylon water pump gear and as well, the side covers and the actual crankcase halves were in good shape as well. As the pistons were first over size, it looks as if the engine had been rebuilt, and then blown up very soon after putting it back on the road.  I’m sure I will be able to use a few of the engine components in other projects at some point.

You can see what the plan is, and follow along on the project progress on the 1973 GT750 project site located here.

1973 GT750 Suzuki Rebuild

For my next project (you can see a list here of what I have planned or completed)  I have picked up this 1973 GT750 basketcase in Rubbermaid tubs from a fellow in Kincardine Ontario – basically after hauling a load of items down east for our son’s I was not prepared to come back empty ! It was advertised as being a 1973, but in truth it was a real dog’s breakfast with parts and pieces from several years, although the tank, side covers, frame, front forks, headlamp, radiator side covers, radiator surround, carburetters and exhaust were from the right year. I was happy to get it if only for the parts – the carbs by themselves were worth the cost of hauling it back, plus I expected to be able to salvage at least something from the two engines also included in the deal.

After doing some soul searching, I’ve settled on a way forward. Basically the engines that were included with the basketcase are the wrong ones for the model year, and in any case are not in the best of shape – one has a holed piston, and the other has had some sort of catastrophic mechanical failure that has destroyed the cylinder barrel as seen in the photo to the left. I’m assuming there are still bits of a connecting rod under the leaves at the bottom of the barrel but given the general condition there doesn’t seem to be much there worth saving other then the engine side covers and (perhaps) the water pump. The second engine is slightly better in that it isn’t seized, and other than the holed piston there doesn’t seem to a lot more wrong with it but of course till I tear it down I won’t know.

As I was picking through the Kincardine Rubbermaid containers, Fred and Janice here in Calgary of the local ‘Loyal Order of Water Buffalos’ sub chapter of the CVMG – Rocky Mountain Section, made me an offer which I couldn’t refuse of another 1973 model year bike. This one has been sitting outside since Adam was a boy and is a very tired old soldier, but it does have the right engine for the model year and a few other good bits and pieces so it should work out, assuming that I can get the engine apart – getting the barrels off these older GT750’s can be next to impossible. I’ve borrowed Fred’s puller which should make it easier, but we’ll see.

So the plan then is as follows:

• Keep the Kincardine Rubbermaid Suzuki rolling frame seen below to the lower left as it is already nicely painted. The front end has a few problems, as does the centre stand, tank and side covers, but I have some parts on hand left over from the GT/GS750 project bike I finished earlier this year so I don’t expect too much trouble – plus it has paperwork which is a pleasant bonus !
• use the engine, instrument cluster, radiator and a few other bits from the donor bike from Fred and Janice seen in the middle photo – most of the rest of the bike, including the frame, is too far gone to salvage. The tank, while not really usable, does have the right pattern for the paint and so will be useful as a guide.
• and at some point later this year or next, I’ll have something that will look like the photo to the lower right !

The next step then is to strip the donor bike down, salvage what I can and also go through the Rubbermaid tubs that came with the Kincardine bike to see what should be kept from it. As with my other projects, I’ll keep a record of what I do and problems I run into on a project site, which for this project will be here.

It should at least keep me out of trouble !

I bought this 1973 GT750 basketcase in Rubbermaid tubs from a fellow in Kincardine Ontario – basically after hauling a load of items down east for our son’s I was not prepared to come back empty ! It was advertised as being a 1973, but in truth it was a real dog’s breakfast with parts and pieces from several years, although the tank, side covers, frame, front forks, headlamp, radiator side covers, radiator surround, carburetters and exhaust were from the right year. I was happy to get it if only for the parts – the carbs by themselves were worth the cost of hauling it back, plus I expect to be able to salvage at least something from the two engines also included in the deal.

In the photo to the lower right, you can see where I’ve stuck some of the bits together just to see how it looks. The seat is one that  had on hand and as you look at it, it almost looks like a real bike. In fact there are a few problems. For example, many parts appear to have been damaged in the course of either disassembly or attempts to repair which will necessitate doing some parts hunting. Most seriously, I’m missing the right version of engine.

After doing some soul searching, I’ve settled on a way forward. Basically as mentioned previously the engines that were included in the basketcase are the wrong ones for the model year, and in any case are not in the best of shape – one has a holed piston, and the other has had some sort of catastrophic mechanical failure that has destroyed the cylinder barrel as seen in the photo to the left. I’m assuming there are still bits of a connecting rod under the leaves at the bottom of the barrel but given the general condition there doesn’t seem to be much there worth saving other then the engine side covers and (perhaps) the water pump. The second engine is slightly better in that it isn’t seized, and other than the holed piston there doesn’t seem to a lot more wrong with it but of course till I tear it down I won’t know.

As I was picking through the Kincardine Rubbermaid containers, Fred and Janice here in Calgary made me an offer which I couldn’t refuse of another 1973 model year bike. This one has been sitting outside since Adam was a boy and is a very tired old soldier, but it does have the right engine for the model year and a few other good bits and pieces so it should work out, assuming that I can get the engine apart – getting the barrels off these older GT750’s can be next to impossible. I’ve borrowed Fred’s puller which should make it easier, but we’ll see.

So the plan then is as follows:

keep the Kincardine Rubbermaid Suzuki rolling frame seen below to the left as it is already nicely painted – the front end has a few problems, as does the centre stand, but I have some parts on hand left over from the GT/GS750 project bike I finished earlier this year so I don’t expect too much trouble – plus it has paperwork which is a pleasant bonus !

use the engine, instrument cluster, radiator and a few other bits from the donor bike from Fred and Janice seen in the middle photo – most of the rest of the bike, including the frame, is too far gone to salvage. The tank, while not really usable, does have the right pattern for the paint and so will be useful as a guide.

and at some point later this year or next, I’ll have something that will look like the photo to the lower right !

The next step then is to strip the donor bike down, salvage what I can and also go through the Rubbermaid tubs that came with the Kincardine bike to see what should be kept from it. It should at least keep me out of trouble !

9,574 km Later …..

We are safely back home again after our trip down east – we were away 20 days, although just nine days were ‘travel’ days and we covered a total of 9,574 kilometres. The average fuel consumption over the entire distance with the Volvo while hauling a trailer, turned out to be 10.6 l/100 km or about 26.7 miles per Imperial gallon and we averaged 84 km/hour over the whole trip. I improved on the fuel consumption from what I was able to get last year, by just lowering the rear tail gate on the trailer to reduce its wind resistance – doing so basically paid for about three tanks of gas and so was well worth it. We had good visits with both my brothers, a few friends and also relatives on my wife’s side of the family, and best of all spent some time with our two son’s. The high point was the graduation of our younger son Derek at York University.  All in all, a very successful trip.

We took the trailer so we could deliver a load of items to our sons in Ontario, and rather than come home ‘empty’ we dragged back a 1973 Suzuki GT750 basket case seen in the photo to the right which is in a very sorry state, but which does have a few parts and pieces I can use elsewhere if I don’t actually try and restore it. As well, tucked away in one of the boxes, was a possibly rare Clymer repair manual – it is a third printing covering only the 1972 380cc through 750cc Suzuki triples, is dated 1974, and appears to have not been used so I’ll add it to the collection in my library. I need to clear away a few of my other projects before I decide what I’m going to do with the basket case, so it will probably just sit in a heap in a corner of the garage till next year at which point I will include it on my project web site.

While travelling we usually try to use Shell fuel stations as they are after all the folks paying my pension, but after having travelled to both the east and west coasts of North America a couple of times in the past year I can say with some authority that Shell really doesn’t always make it easy for expressway and turnpike travellers to buy their products. We several times fuelled up at Esso/Exxon or some other brand simply because they had advertised ahead on the highway so we knew they were there when we needed fuel – while a Shell station may have also been available, we many times didn’t find out about it till we had passed it. The other thing was being able to easily get to a station that you knew existed. Many years ago, a fellow I worked with by the name of Jerry Beneteau told me that the secret of a successful service station was ‘good dirt’ – it appears that this useful insight has been lost by Shell retail in the USA and Canada, as in a few cases, having confirmed that a Shell station existed, getting to it was not convenient from the perspective of a highway traveller wanting to just fill and go with the least fuss and time investment.

The other thing I really started to find annoying was in the USA being sometimes asked to enter a zip code at the pumps when paying by credit card – of course, being from Canada I don’t have a #$%@ zip code so I then had to go into the office and negotiate with the sales clerk which sort of defeats the whole idea of speed and convenience in today’s self serve world.  In one case (not a Shell station) , I actually had to prepay and then go back and get a refund for the amount I didn’t put into the tank !  I can accept the idea of doing something to reduce fraud, but modern credit cards have PIN numbers so rather than creating a new, non-standard method I don’t understand why they wouldn’t just use what already exists ? It seemed to me to be a slightly stupid, non-customer focused process.

When I was working at Shell, I recall regular discussions amongst the retail folks about how to boast sales – I think one easy way would be to stick a few senior executives in a couple of cars for a few weeks, and have them do some actual ‘on the ground’, coast to coast highway learning to see what it looks like from the customer side, rather than from the inside of their offices.  I’m pretty sure there would be a few changes made really quickly if they did !

Windjammer

Every once and a while, you get pleasantly surprised by the unexpected kindness of a stranger – and even less often by someone who has a ‘name’ in the business world. This happened to me recently when I went looking for some parts and pieces to refit my Vetter Windjammer IV for one of my GT750 Suzuki’s.

Back in 1973 when we married, in addition to my newly wed wife, I must admit that I also lusted over what was then the Rolls Royce of motorcycle fairings made by an outfit in the US owned by a guy called Craig Vetter. Back then, motorcycle manufacturers generally did not provide much of anything  other than the actual motorcycle, and there was a good sized aftermarket industry to provide windscreens and pannier bags. Initially this accessories market, with the exception of Harley Davidson accessories, was based in Europe, but as nice people started to meet each other on Honda’s in the US (still, I think, one of the most clever advertising angles invented) there gradually grew a market for similar hardware in the USA and Canada.  Prior to Craig Vetter developing his line of aerodynamically styled  fairings, much of what was on offer was somewhat flimsy, rattled a lot, often looked like an after thought, didn’t really offer much in the way of weather protection and usually did not offer any storage capacity – the Windjammer in contrast was solidly built, solidly attached, provided good weather protection and lots of storage and really looked good. In 1974 when I bought my first new bike, a Suzuki GT750, as can be imagined I immediately (well almost immediately – it took a few months to scrape together enough money to pay for it) went to get a Vetter fairing for it – the model was called a Windjammer II.

To say that I was in heaven once I had the fairing mounted on that bike would be an understatement – it was in many respects a dream come true as it made such a difference when riding it.  Fast forward a few years, and most motorcycle manufacturers woke up to the idea that they could build and sell their own lines of fairings, bags and fittings and while imitation is said to be the highest form of flattery, together with changing tastes of motorcycle owners, they basically killed the after market industry for this sort of accessory. The Vetter product line eventually ceased production in 1985. Craig Vetter had actually sold his business in 1978, but has continued to be involved with motorcycle design and various projects including mileage competitions to this day. He was inducted into the Motorcycle Hall of Fame in 1999, and if you follow the link there is a good bio of him and his design accomplishments.  

Returning to that 1974 motorcycle – my pride and joy was actually stolen in the fall of 1974, and while I went on to own other bikes and makes and models of fairings I always thought that Suzuki GT750 with its Windjammer fairing looked the best of any that I came to own. When I picked up another Suzuki GT750 in 1986, as may be expected, one of the first things I did was track down and install a Windjammer fairing, although by that time new parts to fit the Suzuki could not be ordered and I actually had to make my own mounting hardware.  

So here it is 35 years after my first Windjammer purchase.  If you check eBay, there is still a very active market for these accessories, and you regularly can see various Windjammer models for sale, as well the the matching Vetter carrier bags together with mounting hardware. The internet and I suppose specifically eBay has provided an easy way to eventually locate almost all the bits you need to put a set together. As I recently dug around the internet looking for parts to refurbish my Vetter fairing, I was pleasantly surprised to find that after all this time Craig Vetter himself is still providing some limited support for his creations in the form of advice, replacement trim pieces and hardware. Better still – he and his wife Carol will actually cheerfully respond in person to queries and requests, and he even sent me a photo of himself on a 1972 GT750 with one of his fairings mounted on it ! You could have knocked me over with a feather, I was that surprised, as this sort of business behaviour is such a welcome contrast to so many other businesses that I deal with these days.  

Personal responses, cheerful advice and friendly service – that’s a precious thing in this day and age, and perhaps a small part of why Vetter fairings are still as sought after as they were 35 years ago. Of course, the fact they still look fantastic must also have a bit to do with it !

Calgary Motorcycle Show

Well, the weekend has come and gone and I spent yesterday (Monday) just puttering around the house after four solid days at the Calgary Stampede Grounds in the Roundup Centre where the 2009  Calgary Motorcycle Show was held. This is a travelling  show that visits several cities at this time of year, providing a welcome break from the winter blahs, and while I haven’t seen the final attendance figures it was a very busy place in our corner of the building.

The local Rocky Mountain chapter of the Canadian Vintage Motorcycle Group (CVMG) had a large number of vehicles on display ranging from a 1935 BMW through to a 1983 Suzuki Gamma, and as Suzuki was featured this year, we had good selection of this make on hand. Front and centre on the RMS CVMG display was Wade’s immaculate and all original 1972 GT750 seen to the right. Also on display was Fred’s 1976 RE5 rotary together with a cutaway of the engine which we (mainly Janice actually) cranked over by hand for hours. It never failed to attract a lot of attention as you really need to see it operating to appreciate just how different an engine design it is, and many people are not aware this type of engine was actually ever used in a motorcycle. It was also very interesting to watch people’s faces as they walked around our display – clearly seeing these older bikes brought back a lot of memories for many people, and you constantly heard parents telling their kids about how they’d had one just like one of the ones on display. The other interesting thing was the number of folks who had been given their father’s or grandfather’s bike which had been sitting for the last who knows how many years in a garage or shed, and who now were looking for information and help to get them running again. Possibly a few of these will be on display next year !

Getting the bikes to the show for all of us was not a lot of fun on Thursday as it was -15 C and snowing, but everyone chipped in and helped each other to unload and push the bikes through the snow in the parking lot and into the Roundup Centre.  Fred set the record for most trips, but I think the one that came the furthest was the absolutely beautiful 1951 Vincent Black Shadow owned by a club member north of the city. Perhaps one of the biggest concerns (other than having an accident) was the amount of slop and road spray there was for those of us using open trailers – after the hours of shining and polishing, the last thing you want is slush, sand and salt spray all over your pride and joy ! Fortunately the cover I had worked well, and I had only a small amount of tidy-up to do once I’d unloaded.

My own contributions were my 1974 GT550, and my project bike with the burgundy tank seen to the left, and which a few of the members call a GTS750 as it is a GT/GS hybrid. For me personally, completing the project was the culmination of six months of very satisfying and rewarding work, and the perfect tonic as it took my mind completely away from cares, pressures and concerns of my former employment, and allowed me to fully disconnect and move into retirement mode.  All in all, it was a great experience, and I’m already looking forward to next year’s show.

Next on the agenda is to get the GT550 running and also do some work on my Yamaha YA6 along with the other usual household items – I suppose at some point I may consider looking for a part time job of some sort, but at the moment I’m not sure where I’d be able to find the time !

A Good Day !

Well – today was slightly more notable than most for me as a) it was my birthday, and b) I finally finished my GT750 Suzuki project bike ! I did a small photo shoot out in the -15C weather and the heaps of snow piled at the front of the house and (not that I’m in any way biased of course)  I think  it looks OK. As an added bonus, it also runs although till some of the snow melts, I probably will not be driving it too far.

It will be on display at the Calgary Motorcycle Show this coming week – perhaps I’ll see you there !

 

Additional photos can be seen here.

Ignition – GT750 Project

There are several electronic ignition options available for the GT750 and include the Boyer Bransden, Newtronic , and roll your own as described on the Pink Possum web site.  

 

If you search the web, the kit that seems to have the best reviews is the Newtronics kit as it is packaged as a Suzuki specific item – for example you supposedly do not need to butcher your wiring to install it.  See Gunner’s write up on the Newtronic unit here. However, as of this writing Newtronic are no longer in business, although their SU6 kit can still be found if you look, and the new owner - Autocar - may start selling them again. Given availability issues, I went with the Boyer Bransden unit which I bought from Walridge Motors who are the Boyer distributors here in Canada. Walridge Motors is actually a vintage British motorcycle supplier, and they were very easy to do business with, and quite helpful. They also stock the old style metal core ignition wire which is handy for repairing old Suzuki ignition coils if you have the need. 

I won’t repeat what Gunner has mentioned about the Boyer Bransden model KIT00083 kit to fit the Suzuki triples, other than to agree that it is a bit disappointing as it is actually a made over kit intended for a Kawasaki and as such it lacks the correct mounting plate, the correct wiring diagram information or even what I’d call ‘good’ set-up information. Having said that, it wasn’t too hard to figure out and install. I did have to modify the Suzuki mounting plate as the rotor supplied in the Boyer kit was too big for the hole in the centre of the points mounting plate as seen to the left – I opened the hole up with a step drill bit. I also made a rubber pad from an old inner tube to fit under the Boyer contact plate which was probably not really required, but seemed like a good idea as the Boyer supplied plate is not very rigid.  The mounted point plate can be seen in the photo below.

On the plus side – once I had it installed, the bike did start up with no trouble at all so my first impressions are positive. The folks here in Calgary that I’ve spoken to who have the Boyer Bransden unit installed, all seem happy with the product, and several of them have had years of use with no problems at all, so we will see how it goes.

It should be mentioned, that a decent dial gauge is a must for doing the initial setting of the timing, and a good list of available options is offered on Gunner’s site. I actually built my own dial gauge using a cheap unit fromPrincess Auto (part 2970986) which was on sale, and an old NGK spark plug which I modified to be a holder. It has worked well for me for years at a total cost of less than $10 CDN and is shown below.

Carburettor Rebuild – GT750

With the engine in the frame, and the electronic ignition fitted in my GT750 project bike , it was time to dig into my box of bits to see what I could do in the carburettor department.

The local Water Buffalo folks have been urging me to use the Amal style VM 32 carbs as used on the early GT’s, as these do provide better throttle response and also flow better than the Mikuni constant velocity (CV) BS40 carbs used on later models. In the interests of simplicity, I plan to start with the later style CV carbs and then look at replacement options later as they are (I think) easier to set up and will require minimum modification to my current configuration. If I use the VM carbs, then I would have to find a three-into-one throttle cable, as well as the handle bar mounted choke lever and its cable assembly, fiddle with the air inlet boots on the  engine as they are a different size,  modify the air outlet from the air box as that is also different (or switch over to carb mounted air filters) and switch to a cable actuated oil injector setup rather than use the CV style pull rod.

Frankly – I just don’t have the energy to start making this number of changes at the moment, and since I have access to additional CV units via the local CVMG club to supplement the box of parts I’m starting with if required, then CV it will have to be. One change I will be making is to rejet the main jet on the centre carb to match the two outside ones as I will be using a three into three exhaust pipe setup, rather than the stock setup in which the centre cylinder exhaust was split into two pipes.  For a main jet, I’m starting with a 115 rather than the stock 110 and we’ll see how that works. The other thing I’d like to do, but will probably pass on for the moment is to install the ‘anti-surge’ fix that was detailed in Service Bulletin GT-36, March 11, 1977 and which can be found here. As I will not be using a stock exhaust system I thought I’d wait and see whether it will actually be required. 

I used the Keyster KS-0029 kits to rebuild the carbs – everything they supplied fit just fine, but I was slightly disappointed that the small o-ring (part number 13295-31210) for the needle jet was not included, nor was the fuel filter (13376-65010). Both of these are still available from Suzuki, but it would be nice of Keyster to add them to the rebuild kit just to make it fully complete. These kits are available all over the place and can be picked up on eBay for between $15 USD to $30 plus shipping.  Luckily the kits do include new starter plungers which are not available from Suzuki, as these were all noticeably worn at the shoulder  where the actuator engages it. The photo to the left is slightly out of focus, but gives the general idea.

 The other problem I had (other than the usual corrosion and cleaning items) was that the oil pump arm was missing the small plastic ball used to connect the carbs to the oil injector pump rod.  Each of the available carbs I had all showed the same problem as the metal bush the ball mounted into was so badly worn that it wouldn’t stay. Fortunately, Fred in the local CVMG had a spare carburettor set I could use for parts, and so I swapped out the shaft as can be seen in the photo to the the right. My younger son Derek handled the metal polishing of the carbuerettor caps, and he did a nice job of making them look almost new again ! 

So – now I finally have a set of carburettors ready to go so the next step will be to see if I can get the engine started !