Ralph with part two of curing his six’s temperature issues.
Last month I started dismantling the smoothly beating heart of my straight-six water-cooled leviathan Kawasaki. I have to mention here, that I have no interest in safe bikes with ABS, traction control, eleventy billion suspension settings and clocks that look more like an ipad; I want a raw exciting bike that has to be tamed. The Z1300 does that in spades, or at least it did before the water pump drive went south. When I left you I had just removed the longest cylinder head I have ever seen on a motorcycle and am ever likely to. At this point I will make note here that when stripping any bike ensure that you have lots of containers to put the parts in. I am a regular customer of an establishment in Bristol that sells lots of well cheap household goods and hardware. Now while I don’t buy those cheap Chinese hacksaw blades, that cut equally well on all four sides, I do buy lots of their food containers; like Tupperware but cheaper! They are so cheap to buy that I buy dozens at a time and despite the very reasonable price tag they are actually very hard wearing. If you follow my lead always get some oily fingerprints on them straight away, lest your ‘She Who Must Be Obeyed’ purloins them for their original purpose as mine has previously tried to. They don’t seem as attractive once covered in oil. I also use large multi-compartment boxes when I want to keep a group of similar components together but separate, if you get my gist, e.g. cylinder head parts. Lastly there are the larger clear plastic boxes I use, but these are often quite fragile, particularly when you put bigger heavier parts in them and I consider them to have a relatively short shelf-life, if you’ll forgive the intentional pun. If you store parts in groups as they are removed, it makes refitting far easier, particularly if it’s not a job you’re going to be able to turn around swiftly, which is often the case with projects. I forgot to drain the oil before I started the job, which was rather remiss of me as it’s much more reluctant to come out when it’s cold. I always thoroughly clean my oil drain pan once I have finished with it, because I need to know that any crap I find in the bottom is from the engine I am draining rather than from somewhere else. Once I had tipped away (for recycling)
most of the six-and-a-bit litres of oil, there was quite a bit of detritus left in the bottom of the drain pan. This alarm bell signalled that it was time to remove the mighty sump and investigate the source of this debris. Once the 17 M6 bolts had been removed I was treated to a horrendous sight: the sump was full of crap including huge amounts of instant gasket! There was a die-cast oil pick up from which I pulled even more vines of the stuff. I unscrewed this from the bottom of the engine where I discovered it has a gauze which when removed showed even more of the swathes of crap gasket goo. Instant gasket and pre-insulated electrical terminals are two products that fill heaving shelves in DIY auto shops, which have no place in any motorcycle workshop and cause almost as much damage to motorcycles as numpties who don’t think they need torque wrenches. The problem is that Freddy Numbskull liberally lathers the stuff onto the mating parts and sometimes gaskets, before over tightening the fasteners as he clearly doesn’t need a torque wrench. The stuff is squeezed out either side of the joint where it sets and then falls off, eventually into the crankcases. Often lumps of it will block oilways causing bearing surfaces to be deprived of the lubricating oil which will shorten their life massively. Judging by the amount of the rubbery shite I pulled out of this engine, I’m very lucky there wasn’t more damage than there was. I gave the sump a very thorough clean with degreaser, finishing off with brake cleaner. I then unbolted the manifold containing the oil pressure relief valve and the oil level sensor which was only added for the 1981 A3 model onwards. A very good idea, though it shows its warning on the same panel light as the oil pressure, so when it lights up you don’t know where the warning is from. As I had it this far apart, I thought I may as well check whether the sensor works or not. The sensor has a float that runs up and down a central post containing a reed switch. There is a permanent magnet in the inside of the float. Regular switches have contacts that are pushed together by some form of lever; simple reed switches have contacts that are kept apart by the spring of one of the contacts. The contacts are encased in a glass tube which contains an inert gas to prevent any arcing from burning the faces of the contact points
as contact is made or broken. When a magnet is brought near the switch the sprung contact is attracted to it and it is pulled towards the magnet and thereby completing the circuit. If you’re confuddled by my inadequate prose, see the drawing I have crafted to illustrate the workings. Removing the sensor was easy, first the wire is released by undoing the screw and then the two no. 3 JIS securing screws were removed. I actually used pukka JIS screwdrivers that have just been made available by Laser Tools. As I have been made aware that there is a desire for these screwdrivers among bike fettlers, I took a set in to test before considering them for Biker’s Toolbox. I have to be honest and say that I was agreeably surprised and so now stock them. Once removed I simply set my multimeter to the resistance range and attached the black lead to the earth plate and the red to the terminal for the sensor wire; it doesn’t matter a jot which way around you connect them from an electrical perspective, but it is good working practice to always use the black for ground. As the switch is pretty tiny, and thereby not suitable for switching much current, Mr Kawasaki decided that rather than carrying the full current draw of the warning lamp bulb and allied wiring, it would be better to get the switch to fire a transistor that could act as a solid state relay. That is why when the float is in the highest position, indicating that the oil level is correct, the switch is closed with a resistance of less than half an ohm. When the oil level is lower than ideal, then the float drops and the switch opens as the magnet no longer holds the sprung contact closed and the resistance will be infinity ohms on the measuring meter. This system has the bonus that should the wire from the sensor break, then the warning light will illuminate to identify a problem. I am currently debating fitting an additional LED warning light, so that I will have a separate oil warning for level and pressure failure, because when riding one says pull in the clutch and hit the kill switch immediately and the other means get some more oil as soon as – a big difference in imperative! Because the beast was exhaling the odd puff of smoke and using a minimal amount of oil, my next task was to examine the bores. They were clearly a tad glazed, so would definitely benefit from a light hone and a new set of rings, but what of the wear? I dug out my bore comparator, DTI (Dial Test Indicator) and my new
digital micrometer that I had so lavishly treated myself to in a moment of wild extravagance. Because of the level of accuracy required with cylinder measuring I decided to check the calibration of the mic with the 50mm standard the instrument shipped with. Next, I gently clamped the mic frame in the soft jaws of my bench vice and set the mic to exactly 62mm – the size the bore should be. I selected and installed the correct anvil from the bore comparator set to read the range of bore we’re dealing with. I then fitted my digital DTI to the comparator and set it to read zero at exactly 66.000mm with the reading head between the anvils of the micrometer. I fed the reading head into the barrels and took readings at all the points demanded by the factory manual. The greatest oversize was 0.04mm which is well within the tolerance of up to 0.1mm over size or a difference between the maximum and minimum readings of up to 0.05mm. At this point I decided to feed the engine a new set of rings, which was costly enough; I dread to think what the cost of a re-bore and six new pistons would have been. Next month I will be removing the barrels and performing some head work that became quite expensive. ■ www.bikerstoolbox.co.uk
Removing the screws that attach the sensor.
A side view of the oil level sensor. The big black bit is the float.
With the meter on the resistance range and the float down the reading is open circuit – ∞Ω.
Connecting my meter on the continuity range with the float pushed up showing the switch is closed.
With the meter on the resistance range and the float up the reading is closed circuit – 0.2Ω.
Loosening the screw that secures the oil level sensor wire.
The larger clear plastic boxes are useful for storing larger components.
That doesn’t look healthy!
The sump sans crap.
Instant gasket: why?
Unbolting the manifold that contains the oil level switch and oil pressure relief valve.
Now that’s what I call a head!
Multi compartment boxes are great at keeping components of one section together, but separate.
The Beast in Snowdonia on our tour of England, Scotland and Wales, when she was black. Ahhh happy times!
Permanent magnet Measuring the bore.
Zeroing the DTI at the correct bore size.
Checking the micrometer calibration with the ‘standard’ it is supplied with. It was spot on!
The mic set at the bore size – 62mm.
0.03mm oversize – that’ll do nicely.