Workshop

Suzuki GT750 workshop rebuild We've departed from the magazine's series slightly and joined the rebuild on reassembly, mainly because this was a seven parter in print. We've honed it to four. Our bike is a 1976 registered GT750A, engine no. 74465, frame no 81196, of which approximately 14,000 models were produced. The engine number and…

Continue reading »

Makes notes before disconnecting loom… An average 1970s 250 weighs around 150 kilos and if we assume an approximate 50/50 weight distribution then the front steering races are coping with a 75kg load whenever the bike is off the stands. Factor in a rider and we’re looking at least another 35 kilos over the front…

Continue reading »

Adjusting carb throttles Assuming you run a Japanese four cylinder motor you will almost certainly have four carbs, one for each pot. When you  open the throttle you need all four carbs to respond at the same time so each cylinder gets the same amount of fuel and works with its neighbours. In real life…

Continue reading »

BSA A7/A10 service notes (pdf) BSA's 500cc parallel twin, the A7, was introduced in September 1946, though the initial design was laid down before 1939. It was a bit of a 'committee' engine — the basic layout is attributed to Val Page, Edward Turner laid hands on it during his time at BSA during the…

Continue reading »

Give your exhausts an overhaul… There are now no longer any hard and fast rules to decoking two-strokes and the changes in two-stroke oil technology since the 1970s means a one-size-fits-all approach is no longer viable. Before the advent of ester-based synthetic oils it was pretty much guaranteed that the time-honoured caustic soda de-coke method…

Continue reading »

1970 Honda CB750K2 Our bike is a CB750 K1 manufactured in 1970 for the American market and is number 28,208 off the production line that year, with production starting from frame number CB750 – 1044650. The K1 has cosmetic and detail changes from the original model and was the first model to arrive here in…

Continue reading »

Honda CB750 engine, awaiting overhaul Click on the image gallery for step-by-step images and captions. Image captions Picture one: To begin the stripdown I've removed the points cover from the right-hand side of the engine. Unlike later Japanese fours this is a chromed steel pressing. Removal reveals a conventional points set-up with two sets of…

Continue reading »

Honda CB750K2 overhaul’s nearing the end… See the step-by-step instructions in the image gallery. Picture one: Last month I finished off the top end of the engine. Now I'm going to complete the motor before fitting it into the frame. First off, the gear selector mechanism engages into the right hand side of the lower…

Continue reading »

All done… See step-by-step images in the gallery. Image captions Picture one: The original wiring on this bike was in remarkably good condition, and I've had to do only a little cleaning up and retaping before refitting the harness. The major electrical components mount in the usual place to a plate on the left of…

Continue reading »

Yamaha 650 XS1 Our Yamaha engine wasn’t in bad overall condition, as we discovered in part one. A full strip of the engine revealed no major problems, only the front camchain slipper blade being in need of replacement. I’ve had the head and barrels bead blasted and we’ve opted to replace the camchain. So, armed…

Continue reading »