Saturday April 12th 2025

 Saturday April 12th 2025

Kawasaki KZ550 Limited

The new second hand passenger grab handle was installed and A.J. finished off the tail end of the bike. He then worked to polish up the generator and sprocket covers and even fitted the bikes original number plate.  The most significant job that remained to be completed was to install the replacement front brake master cylinder.  It had been delivered after the previous workshop session but in a senior moment I had forgotten that it had been sent to Phil and wasn’t actually in the workshop and so spent some time hunting for it, before realisation dawned.  Emma the bike's former owner visited the session and it was great for her to have a chance to see the transition  the bike had been through during its long journey with the club.

Kawasaki KZ550 Limited completed with passenger grab handle and number plate.

Suzuki 1200 Bandit.

Now it was time to install the carburettor repair kits.  The main benefit of this was that new float needle valves could be fitted along with the O-rings designed to seal them tightly into the carburettors.  This would prevent a repeat of the torrent of fuel spilling onto the workbench that happened the first time we filled the carburettors with fuel. Along with them Guy fitted other new O-rings,  and fitted new diaphragms to the carburettor slides.  The #110 main jets that came with the carburettor repairs kits were installed in place of what looked like #109 jets that had been fitted to them. All the float heights were checked and set as near to the specification found in the workshop manual as possible (14.6mm).  This was a tricky operation as the float valve pivot has to be held in place and the weight of the floats could not be allowed to compress the spring in the float needle valve. New rubbers had been installed into the air box and now it was time to install new rubber manifolds between the carburettors and the cylinder head. Once the oil feed pipes had been reattached to the rocker cover, it was time to refit the carburettors. The first thing that was done was to reattach the throttle cables, or at least just attach the opening cable.  The closing cable was beginning to break and in such bad condition that it would have to be replaced.  Getting the opening cable's nipple into the quadrant was a two man effort. It was so close to some adjacent pipework that the throttles had to be held open to get enough clearance.  Even then, the cable was only just long enough to get the cable inner around the quadrant allowing it to be fitted in place. With the air filter box loose in the frame it was easy enough to pull the bank of four carburettors into place.  Getting them to push into the manifolds took a little more effort. It needed the clamps to be fully undone and the application of a hefty helping of brute force (but no ignorance this time!) to get the carburettors to slip into them.  Once they had popped into place there was then the challenge of getting the air filter box rubbers over the oval carburettor mouths. This meant removing the center clamps entirely and a little judicious fiddling with a small screwdriver to encourage them to slip into the correct place.   A couple of large screwdriver handles were wedged between the air filter box and the adjacent frame to push the air filter box forward keeping it in place whilst the clamps were installed. Now it was time for the moment of truth.  The exhaust couldn’t be installed at this stage as new studs would be needed before it could be fitted properly.  The air filter box wasn’t rebuilt as it would all have to be taken apart if the carburettors had to come off again. Once a fully charged battery was installed the ignition was turned on. Well it was more a case of jiggling and wobbling the key.  Even when the power was on, nothing happened when the starter button was pressed. Eventually the starter relay was located and the plastic cover over its terminals was removed.  Graham bravely shorted its terminals but wasn’t brave enough to keep the screwdriver on the terminals for long enough to start the engine.  Guy, on the other hand, was far braver and kept his long nose pliers on the terminals long enough to turn the engine over till it started. All four cylinders started together (See video below).  For reasons not known, the opening throttle cable was keeping the throttles from fully closing and so the engine raced a little. Once it was removed from its mounting point the engine even ticked over.   Having initially been fuel tight, number 4 carburettor started to overflow a little and would most likely have to be taken apart again. The fact that it wasn’t an instant deluge of fuel, suggested that some dirt might have found its way under the float needle valve. Whilst the engine was warm the spark plugs were removed and the compression pressure was checked on cylinders 1,2 and 4.  For reasons not yet established the pipe of the compression tester couldn’t be persuaded to screw into number 3 cylinder’s spark plug hole despite the spark plug fitting easily enough. The results of the compression tests can be seen in the photos.  Cylinders 1 and 4 were nice and healthy.  Cylinder 2 got there eventually so if there was any lack of power or dodgy tick over it could well be our first port of call.

Original #109 main jet - or so we think, the number isn't very clear.

The very tricky to measure float assembly in place. 

No 1 cylinder compression.

No 2 cylinder compression

Number 4 cylinder compression.

Ready to run.

Kawasaki Z250 Scorpion…

Keiran worked hard to perfect the bike’s electrics.  He installed a new back brake light switch, two new indicators and a new pilot light bulb and then got everything working with the exception of the pilot light bulb.  This may in fact have been a front parking light bulb.  The ignition switch did not seem to have a parking position which may have been the reason for it not coming on.  This would have to be investigated further if electrical perfection was to be achieved. Keiran also noticed the absence of the small section of wiring harness containing the idiot light bulb holders that would allow them to be properly fitted into the clocks.  I am sure we could find one somewhere.

Perfecting the electrics. 

Ducati 250 Single racer…

Jon arrived at the session clutching a small cardboard box containing an electronic ignition system for his bike which he and Keiran set about fitting.  By the end of the session more work was still required but the bike edged ever closer to regaining its long lost spark. Somewhere would have to be found to locate the little black box but that was a minor trifle.  We all waited with bated breath to one day hear the bark of the engine’s exhaust and maybe to even see it being ridden in anger on the track as intended. 

Bringing back the spark of life.