For the last few weeks Spotty and I have been playing with my 1977 KZ750. It was a "Freebie" from a work colleague who has owned it for many years, but last rode it 10 years ago. Last weekend we put a battery in it and put a gallon of fuel in it, but as soon as we turned on the petcock fuel just ran straight thru the left carb and out onto the lift. I took the carbs off and brought them home, and stripped them for a clean. They sure needed it.
The reason why the fuel had run straight thru the left carb was because there was a hole in one float, and the float was seized in place, so rather than fight it, I decided to put it in my 30 litre ultrasonic cleaner with the float in place, figuring that the heated bath would loosen it, and it did.
KZ750 Saturday 26 October 2024 by
Terry Prendergast, on Flickr
KZ750 Saturday 26 October 2024 1 by
Terry Prendergast, on Flickr
KZ750 Saturday 26 October 2024 2 by
Terry Prendergast, on Flickr
I emptied a year or so of sludge from my ultrasonic cleaner and gave it a clean out, then tipped in 5 litres of cheap ($15) water based degreaser from Amazon , not expecting much as I'd previously only had so/so results after using Simple Green Aircraft Parts Cleaner ($200 for 20 litres) but I was really impressed with this stuff, 5 litres of cleaner and 25 litres of water, and it ripped off the grease, corrosion, fuel varnish etc.
KZ750 Saturday 2 November 2024 by
Terry Prendergast, on Flickr
KZ750 Saturday 2 November 2024 1 by
Terry Prendergast, on Flickr
KZ750 Saturday 2 November 2024 2 by
Terry Prendergast, on Flickr
KZ750 Saturday 2 November 2024 3 by
Terry Prendergast, on Flickr
This morning we re-installed the carbs, gave the petcock a quick clean (I'll need to take it off the tank again and put it in my little 1 litre Amazon ultrasonic cleaner that I cleaned the small parts in as it doesn't work in the "reserve" position, so it's probably full of crap too) installed clear fuel lines and because I didn't have any new inline filters, I'd cleaned the old ones in my little ultrasonic cleaner too and was happy to see fuel running to the carbs,
Right. Carbs were in place, we knew it had spark, it had fuel to the carbs, we'd done an oil and filter change weeks ago, and installed a new front brake master cylinder last weekend, so there was nothing left to do than press the button, and hope..... It cranked and cranked, but didn't fire. Fcuk. We pulled the plugs and they were wet, but produced a nice fat spark. Hmmnnn. Plugs back in, sprayed some carb cleaner into the airbox, crank, crank, crank, KABOOM!. FCUK! It was ear splitting. We tried again 2 or 3 times, with the same result, no firing, just an ear splitting boom. WTF?
We thought about swapping the plug wires, in case it was firing at the bottom of it's stroke, but as it only has one coil it wouldn't have mattered, so we removed the points cover and removed the points cam from the advance unit and turned it 180 degrees, but it made no difference, crank, crank, crank, KABOOM! Double Fcuk. We replaced the points cam and roughly timed it and adjusted the points gap, but weren't confident that this would make any difference, so were both surprised and delighted, when it fired right up! Woohoo!
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We quickly screwed everything back together so we could take it for a ride! I've never ridden a KZ750, but it seems to have a bit more power than my Yamaha XS650 or even my son's Royal Enfield GT650, and was actually quite pleasant to ride. Considering that it only had a gallon of fuel in it and reserve wasn't working we only did a couple of laps, but it went well.
It has a slight flat spot just off throttle, so I'll take my timing light over next weekend and we'll see if we can't sort that, one blinker globe is dead and the speedo isn't working, but it looks like there's a new one in the milk crate of spares that Rob gave me with the bike, and even though the rear brake works fine, we might flush the brake fluid. There's some dusty corrosion on the engine cases so we'll have to scrub that off, then I need to take it for a longer ride, to see if it's gonna be a "keeper" or a "flipper" I know I can't keep them all, but it's growing on me.........
KZ750 Saturday 2 November 2024 5 by
Terry Prendergast, on Flickr