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 !