KAWASAKI Z1325
Ralph Ferrand gets the motor and pipe in the Zed.
It’s finally time for the dry build and the first job is to get the mighty beating heart of the fire breathing beast nailed into the now stiffened frame. I am way too old to be picking up heavy engines and will use all the mechanical advantage I can get my hands on. The engine was initially in my engine building frame on the top of a roller cabinet so that I could wheel it around and the motor could be turned around through 360° depending on which bit I wanted uppermost. I moved the roller cab next to the bike bench, which I raised to the same height as the tool chest; it was then a simple job of sliding the motor in its jig onto the deck of the bike bench. I bought a fabulous accessory for my bench, which is big post that attaches to the base and deck of the bench with roller bearings so that it can slide along the length of the bench. It has an arm attached to the top with lifting attachments over the bench. If you want to lift something, like a bike or an engine, you attach strops which are further attached to the arm and then the bench deck is lowered. The item attached to the arm stays where it is and can be moved back and forth along the bench. I have an electric hoist above my other bench, but to be honest I find this attachment quicker and easier to use and quite a bit more adaptable. I have an endless strap that oddly arrived with a colour digital printing machine years ago, which is perfect for lifting bike engines. You can see it being used in the photos. I have no idea what its strain limit is, but it has taken the full weight of my Z1300 without breaking or showing signs of discomfort. I did need help to carefully shoehorn the engine into the frame, but there were no real problems and the new lower rear engine mounts fitted around the motor like a glove. There were many considerations for an exhaust for the mighty beast, but my customer had decided he liked the look of a Delkevic exhaust which is British made in stainless steel. At well under £300, I have to admit that I was more than slightly sceptical. When it arrived the quality was extraordinarily good and the fit was as precise as you could wish for. I fitted the pipe without the silencer mounts because I need to build up a rear brake system and have the rear suspension fitted before attaching a mount for the exhaust, but conversely I needed to know where the exhaust went before taking TIG to the frame for the braking setup. Like chess, you have to be thinking a good number of moves ahead with bike building or you can end up in the brown smelly stuff. From a living with the pipe perspective, it is cleverly designed, in that you can
perform an oil and filter change without removing the exhaust, which you can’t with many systems. The swingarm and shock were from a GSX-R1100M, a common donor at the time for mono-shocking classic bikes. I put the shock in my big coil compressor and removed the spring keeper so that I could have a better look at the condition of the unit and its piston rod in particular. Having got it apart I realised that the integrity of the chrome plating on the damper rod had been compromised. The unit is filled with nitrogen gas and as I don’t have the equipment to disassemble and re-gas this type of shocker, it would need to be taken to a specialist. Given the costs of the clean-up and refinishing combined with the unlikeliness of being able to source a new damper rod and the specialist rebuild costs, I concluded that buying a shiny new YSS shock absorber would make far more sense. They are built to a very high standard, are fully rebuildable and actually look rather swish, for a very reasonable price. I fitted the swingarm in place, chocked up on a pile of wood burner food and bolted the shock top mount to the frame with stainless cap screws and attached the shock to it. I then fitted all the suspension linkages. Because the bike was not to be used to hoon down a drag strip and that my customer is fully 20 years more mature than when he last played with this toy, it was decided that we should revert to the standard foot pegs. The big fat swingarm precluded the use of the original rear master cylinder, so I decided to use the master cylinder that Mr Suzuki had fitted to the donor Gixxer. I did however want to retain as much Zedness as possible so bought a reproduction Z1000A2 rear brake pedal. As soon as it arrived on the door mat I took a hacksaw to it and lopped off the original lever that pushed the master cylinder brake rod. Next I grabbed a piece of mild steel round bar from stock and turned down a shoulder that fitted perfectly through the brake lever pivot. I drilled and tapped it M8 and made on
my lathe what I can only really describe as an aluminium button with a countersunk hole to take an M8 countersunk stainless steel screw. As it is difficult to describe, I have drawn a diagram and shown a photograph to make it clearer. I have never seen these for sale, though I am not the only custom builder to use this method as it is a compact, neat and attractive fitting. Next I cut out a triangular piece of mild steel plate to form a bracket to attach the pivot to the frame; once convinced of its position, I tacked it to the frame and then TIG welded it securely in position. As the dry build continues, the welding of things gets progressively more and more awkward. Sometimes you have to tack things in position and then disassemble loads of the build to be able to get enough clearance for the welding torch and filler wire. Other times I only welded stuff on one side and left finishing it off until the frame was fully stripped again. To get the correct leverage on the rear master cylinder piston rod, I needed to measure the original brake pedal and its actuating lever to calculate the length I needed to fabricate the lever acting on the piston in the master cylinder with the new pedal. Anyone who tells you they haven’t used ‘O’ level maths and physics since they left school has clearly never done any engineering! I used a bit of basic algebra to calculate the length of the new lever and the made it from some mild steel bar with a hacksaw and files. I then carefully ground away the plating from the area of the brake pedal where I needed to weld the new actuating lever, assembled it all on the bike and tacked it in place. Once fully welded I returned the pedal to the bike and made a cardboard template for the bracket required to support the master cylinder so that the push rod would be at the correct angle. I
made the bracket from more of my mild steel stock and then offered it up on the bike. After I established the correct position to allow the full piston range I tacked it in place before disassembling it all again to fully weld it. I then turned my attention to making a pedal return spring. The original setup utilised a big curly spring that could be a pain to refit, but that was a non-starter for this bike, so I made another small lever which I welded to the brake pedal for a spring. I machined up a spring attachment post on the lathe. Using a couple of cable ties I set up the perfect spring for the job and was able to mark on the frame the perfect position for the frame spring attachment and then welded it in place as you can see in the photos. The last bit was to make an extension to the original pedal stop because the lever wasn’t in quite the same position any more. Now that the rear brake system was finished, I hung the rear caliper bracket from the wheel spindle in the swingarm slot so that I could fit the brake torque arm in its working position. At this stage I was able to see how much room was left for me to fit an exhaust silencer bracket. It wasn’t terribly straightforward to say the least, but I decided to make it out of 3mm aluminium plate and some bits of aluminium alloy extrusion I had in stock. I was tempted by stainless as it’s easier to weld, but it’s far more difficult to cut and shape. Another bonus of aluminium alloy is that it keeps the weight down. I don’t find aluminium welding particularly easy at the best of times, but in such a restricted space it was diabolical! Once fettled and approved I gave it a good polish and it looked fine and was strong and didn’t foul anything. Next time: oil cooler!