Ralph with part two of cur­ing his six’s tem­per­a­ture is­sues.

Classic Motorcycle Mechanics - - CONTENTS -

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.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.