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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