Winter Layup - 1995 Ducati 900 Supersport

**OddDuck** · 3rd October 2016, 17:23

Annealing and re-using copper washers.

I've done this a few times in the past: take them to red heat, cool them down again (fast or slow, doesn't matter), clean them up and then they're good to go again.

Torch and hearth is nice... I don't have those, so I worked out how to do it on a stovetop. The stainless steel bowl in the pics is there to bounce radiation back down - the element won't go to red heat if it's left open. The bowl does get a bit hot but it's nothing serious. This is probably being a bit harsh on the element so I wouldn't recommend doing it often or for too long. As soon as the washers are red they're done, it doesn't need soak time.

Cleaning up can be done with wet'n'dry etc but there's a jeweller's pickle, used to clean up silver, brass, bronze, copper etc, and it's much easier:

http://www.regal.co.nz/category.php?...+Pre-Po+Pickle

Works fastest if warmed up a bit but will still do the job at room temperature. The washers are shown looped on a spare bit of electrical wire so that they're easy to retrieve from the pickle.

These are all for the engine. Brakes require caution of course, I'd be OK with doing this for mine but a lot of people wouldn't take the chance. New washers are cheap enough.

It's possible to get a check on the anneal when tightening up the bolt or the banjo, the washer will crush while it's being torqued.

**OddDuck** · 7th October 2016, 06:33

Fitting new sprockets to the bike, in preparation for the new chain. Experience on pushbikes has been that there's no saving money here, any attempt to re-use old components is just false economy. A worn part on the driveline will simply transfer its wear to everything else. Motorcycles aren't pushbikes of course, but I could see wear on both front and rear sprocket teeth. They're cheap enough in comparison to the chain anyway, $110 for a sprocket set vs $360 for the chain, so why skimp on it.

So, pull rear wheel off bike again, swap out sprocket. Straightforward job except for the Italian English in the Ducati workshop manual, I couldn't find a torque setting for the sprocket's retaining nuts anywhere. Finally I measured the threads on the retaining studs, at M10 x 1.25, and found the only match listed for that thread: apparently the rear sprocket is a "wheel disc gear" or something similar.

This isn't the first time that this sort of thing has happened. I can see why - mechanic's English uses a lot of unusual words, it's not likely to be taught in a language class, and Ducati had to get someone in Italy to do a translation. I've got to wonder if the German and Spanish versions of the manual are plagued with the same issue. Anyway, it's a good reason to drop the $70 and get the Haynes as well as the OEM workshop manual, these delays add up after a while.

Onto the front sprocket and I found another problem: it wouldn't go on. The splines were a much closer fit than the old sprocket and precise alignment was needed... and then it still wouldn't go on. Close examination showed a burr which had somehow formed right around the inside edge of the spline. This was confirmed by finding that it would fit backwards but would not go on: it would jam up when the end of the shaft came to the end of the spline groove.

I flattened the teeth on a needle file trying to clear the burr from one spline groove and realised that the sprocket had been hardened, then had a look with a Dremel and found that none of my grinding bits would fit properly. In the end I folded up a strip of 360-grit paper and make an impromptu file out of that.

This worked rounded things off nicely, without leaving any sharp cuts or grooves to form stress concentrators. The paper would get ripped up fairly quickly, so there was a lot of re-folding. A quick clean-up with a rag and some CRC, fit-and-try, rework as needed, re-try, and success.

The spline shaft is worn. This shows up as the new sprocket being tight anywhere on the spline shaft that isn't normally used, then quite loose once it's in its final position. When I took the old spline off, there was a lot of road dirt and some rust that came with it. Possibly it's worth treating the spline itself as a lubrication point during chain service - it wouldn't be hard to give it a squirt of chain lube while I'm at the job.

This done, I refitted the back wheel and ran into a problem with one of the tensioners. The chain side tensioner bolt unscrewed easily; the brake side tensioner's bolt jammed up and needed a spanner, then it only went half as far. Hmm. It had been nearly locked up when I'd taken the bike apart, I'd done some work on it with PB Blaster, but it looked like it had jammed up again. In the end I got it out and into the vise, put some bearing grease onto the thread, and ran the screw back and forth until it freed up.

A lot of dirt came out, doing this... it had been badly rusted when I'd first looked at it a few months ago, while the chain side tensioner was in surprisingly good condition under the gunk. It looks like atomised chain lube kept the rust off on the chain side, but road dirt and brake dust did the opposite on the brake side. It was very nearly at the point where threads would rip out or the bolt would snap, when I got onto it - it looks like it's worth treating this tensioner as a clean and re-lube item every time the rear axle comes out.

I didn't quite manage to get the chain on. It turned out to have quite a bit of spare length - of course - and I'll have to take some links off it before fitting.

**Voltaire** · 7th October 2016, 07:30

Are you going to fit a new ignition unit? I've been eyeing up a plug and play ignitech at Fastbikegear.
I've got an Ignitech on my BMW race bike and they are very good.
I gather the original Kukudan ( can't be bothered looking up spelling) units have a pretty horrible advance.

**OddDuck** · 7th October 2016, 17:38

This one?

http://www.fastbikegear.co.nz/index....oducts_id=7290

Impressed with the price already... $400 to replace both Kukosans in one hit, and my originals are in pretty bad shape. The silicone potting's cracking and I had to bake moisture out last winter, then coat them both in silicone O-ring grease to try to keep water out again.

**OddDuck** · 7th October 2016, 20:18

Chain fitting, part one.

I took the old chain and stretched it out full length on a table, then put the new one alongside to get an indication of the right place to break it. I marked this with a cable tie and did a test fit, then got the chain tool out.

The tool itself carries a couple of driving pins (for the common rivet sizes), a pair of setting plates, and a riveting pin. It's very good to work with, but I was new to this so I kept the instructions handy. Everything's got to be clamped up right. If it isn't, a pin can go sideways and break, or the chain can be damaged.

Chain now cut I did another test fit, this time with the greased rivet link in place. Positioning is about right, roughly half-way along the rear axle's adjustment range.

**OddDuck** · 7th October 2016, 20:29

Chain fitting, part two.

After greasing and fitting O-rings and the plate, this has to be driven onto the pins of the joining link. It doesn't press on by hand, unlike a clip link. Pressure has to be applied to the plates but not the pins. The chain tool's clamp plates have gaps machined in for the rivet heads, front and rear, to allow this.

One catch with this operation is that there's no shoulder on the pins to drive the plate up to. It squashes the O-rings instead and that's about as precise as this gets. Following suggestions in the chain tool instructions, I measured an adjoining link's thickness and clamped the plate to the same dimension, then got the riveting head onto the tool and closed the rivets up.

These aren't done by end to end thickness, instead it's the rivet outer diameter. It's supposed to increase by 0.3 - 0.4 mm from whatever it was originally, so I took verniers again and measured before and during riveting. It can be measured with the tool in place and tension still applied.

**OddDuck** · 7th October 2016, 20:38

Chain done, I set wheel alignment (roughly), then chain tension, then finalised wheel alignment.

Chain tension is supposed to be the usual 25 mm up-or-down movement, set at the tightest point in the run, halfway between front and rear sprockets. It doesn't take much eccentricity on the rear sprocket to cause a bit of variation, so it's worth turning the rear wheel a few full rotations to be sure of this point.

My wheel alignment is a bit ghetto: I just put two blocks of 2x4 on either side of the front wheel, lay down on the floor behind the bike, and sight along the rear tyre's front and rear edges on each side. It helps to be about a meter behind the tyre, if I'm too close then the near edge gets a bit blurry.

The bits of 2x4 are there to pack out the front tyre's width a bit so that there's something to sight to. The cut ends of the wood are at the front wheel's turning point so that if the handlebars are turned a bit then it won't affect the alignment too much.

**OddDuck** · 8th October 2016, 14:34

Something I've been wanting to do for a while is to properly tune the carburettors. The big issue with this tuning is measurement.

Techniques: that great Aussie flick Two Hands mentions a mechanic good enough to do it by ear, but that's about all I've ever heard about that. The other common one is to run the engine to various degrees of throttle setting and hold, hit the kill switch, then pull the spark plugs out. The state of the plug nose can tell you if it's running rich / lean / etc.

Something that's become possible in the last few years is to install a wideband A/F sensor and gauge. Pricey, fair bit of work, but I'd get real-time monitoring while riding. I've done my reading and bought an AEM 30-4110NS gauge and sensor kit.

Now to install it... the gauge has to be mounted, the sensor has to be spigoted in to the exhaust, the wiring routed and connected. Straightforward enough.

The kit comes with a mild steel bung carrying the M18 x 1.5 thread needed. The idea is to drill a hole in the exhaust, fit the bung, weld it up and you're away. Unfortunately the kit is intended for the car world, where mild steel in exhaust systems is normal. It wouldn't be a good idea on the Ducati. I've yet to work out what the exhaust pipes are made from, but it isn't magnetic and only oxidised so far despite exhaust temperatures. It's likely to be a 300-series stainless steel. Any mild steel attached to this is going to have serious corrosion problems and won't last very long, so I'll have to make my own bung.

I'll also have to make two of them, one for each pipe, and screw caps as well. The reason for two is to get a sensor mounting position on each exhaust. The exhaust pipes are not of equal length, the intake tracts are oriented differently... it's very likely that carburettor tuning will be slightly different, vertical cylinder to horizontal. I can't measure one and assume the same readings on the other.

The exhaust pipes already carry screw-in sockets, with plug caps. I can't use them. The thread isn't the usual M12 (for a narrow-band O2 sensor), it's something like a 3/8ths 28 tpi, as far as I can tell. I have no idea what Ducati put these on for. There is an adaptor for fitting a wideband sensor to a narrow-band socket, but it's M18 conversion to M12, it wouldn't fit these. The vertical cylinder's socket is far too close to the exhaust port to be used anyway.

So, onto positioning the sensor and marking where the bungs need to go. There are obvious mechanical issues with clearances to engine / swingarm / fairing etc... there's a bit more to it than just those though. This document sums things up nicely:

http://wbo2.com/lsu/LsuInstal.pdf

The sensor has to be at 10 degrees or more to horizontal and 15 degrees or more to vertical, ideally 18 inches down the pipe from the exhaust valve, and not sited somewhere too hot. I had a play and marked up the best options, then took fairing plus exhaust system off the bike again in preparation for cleaning up and welding.

The gauge itself... I'm keen on the idea of vacuum-forming a housing for it, something which bolts on at the right hand side of the instrument panel. Clearances are an issue, so I'll be doing a bit of trial fitting of the positive before I attempt to form the plastic.

**OddDuck** · 13th October 2016, 21:53

Taking the exhaust system off showed something a bit disturbing - there's a big flat filed and bashed into each side of the... wings, I guess they'd be called, of the exhaust system. They've been contacting the ground while the bike's leaned right over.

I've been running with the preload on the rear shock reduced almost as far as it'll go (it worked for the previous owner, but he was a bit lighter than I am), looks like it's time to find the C wrenches for the job and wind the spring up a bit. This is a safety issue - if footpegs contact the ground they'll fold, but if something solidly mounted like the exhaust does, it could unload the rear tyre. Bad things happen next.

I've been spending a lot of time this week thinking about the replacement battery box. On the OEM system, this is integral with the airbox. So is the mounting plate for the bracket which carries the coils and CDI units.

It's not easy to shift coils / CDI units to somewhere else on the bike, unless I hack into the wiring loom. For now, they're best where they are. It's a good location - warm, dry (mostly), close to where they need to be. So the new battery box will have to carry these as well as the battery.

The battery C of G is above the mounting points. The coils and CDI units just add more to the top heavy weight. So the new box has to be mounted in a similar fashion to the old airbox, side to side and fore and aft. It's easy to use the existing brackets on the frame to either side of the battery, not so easy to attach further forward.

Materials and methods: probably 1.6mm sheet steel, folding, and TIG welding. I don't want to hack up the old airbox and I can't work out how to make the shape I need via vacuum forming, so plastic is out.

I was given some 1mm / 10mm ruled graph paper a while ago - it makes it easy to draft up simple planar structures and make cardboard mockups. My first attempt (the red mockup) is a similar idea to the OEM airbox - there are wings streching forward to the original fore mounting points. It'll be strong and relatively simple to make. Unfortunately it won't work: there's a clash with the non-original throttle cables entering the carburettors.

The simpler, smaller brown battery box looks like it'll work. At this point I'm thinking of running the forward support centrally through the gap between the pod filters. From there, I could use the original mounting points, or perhaps clamp to one of the frame's front triangle cross tubes.

**pete376403** · 14th October 2016, 18:38

a lithium (shorai or similar) battery is so light you could mount it on top of the windscreen and it still wouldn't affect the CoG enough to make a difference.
So, battery in the tail piece and that leaves lots of room in the newly vacated battery box for CDI / coils?

**OddDuck** · 14th October 2016, 21:23

I meant the CoG of the battery box only, not the bike itself - sorry if that wasn't clear. My meaning was, if the battery box is down to just the two mounting points on either side, it'll tip forward.

I'd been meaning to refit the original battery (cash is getting a bit tight, so is time) but your suggestion sounds better and better the more I think about it. Back to sketching, I'll see what ideas come up.

**OddDuck** · 15th October 2016, 09:55

I had a look at the bike last night and there's a real problem with installing a Shorai in the tail - proper brackets welded to the frame are needed.

The plan had been to vacuum-form an open top ABS box and screw this down to the existing ABS tailpiece of the bike. It would have been relatively simple to do - a couple of extensions to the existing cable harness, careful tucking and placement of everything, and done. The gotcha here is that the tailpiece of the bike isn't very well attached. The attachment points are thin, not well braced or gusseted, and the plastic itself has flowed under compression and also cracked around the screw heads. Even though the Shorai weighs just 1 kg, it's still another kilo and it's being bounced around on every corner.

Wish I'd seen this while I had the frame out, earlier. Can't be helped now, not unless I want a lot more work. Summer's coming, I'm hearing the bikes out on the good days, time to abandon perfection and just get something that works.

**OddDuck** · 15th October 2016, 21:27

A bit of work over the last couple of days, cleaning up a bit of steel sheet and cutting / drilling etc in preparation for welding.

Techniques, for those interested:

Marking out was done by cutting out the graph paper design and taping down, then ruling / centerpunching where needed. The graph paper saves a lot of time fiddling with set squares and x-y positioning with a ruler.

Cutting along lines was done by angle grinder and cutoff disc. It's possible to get to within the last millimeter if the line's clearly visible and a bit of care is taken. I used a Sharpie to mark hole diameters and cut lines after the drawing was taken off, I find this tends to avoid confusion later.

Drilling the big holes was done with a holesaw, bench vise and a decent quality mains powered drill. A drill press would have been good, though. Slow speeds are needed and it's best if motors are run full speed through gears or pulleys, instead of using speed control circuitry. The motor on my drill gets stinking hot doing this and I've had to do the work in stages. I've used a hacksaw for the internal cuts between holes.

The little cylindrical objects are threaded standoffs, lathed up earlier in preparation for welding in. I'll have to make this structure in two bolt-together pieces, in order that it goes in / out with the fuel tank in place. The original airbox also carried the starter relay mounting bracket, and I'll want a P-clip for the battery vent hose, so those need to be added.

The plates are thick (this'll help my beginner welding) but heavy, that's why a few ovalled cutouts are starting to appear. The target is to try to get around the same weight as the original airbox / battery box, or at least not too much more.

There's quite a bit of gorgeous custom battery box work out there, featuring pierced designs... this is not going to be that pretty. It's just lightening via swiss cheese.

End note: isn't the only way to do this. A quick check on Trademe showed an auction offering sheet steel with laser cutting. A basic DXF file, some bucks, and I'd have had a fold-and-weld solution. That's probably the way to go next time, but for now I'll press on.

**OddDuck** · 17th October 2016, 21:32

Ready for folding and welding. The passivated plate at top is the OEM Ducati coil and CDI mounting bracket.

Holesaw, hacksaw and file might be cheap and easy to set up and get stuck in, but if I do this again it'll be CAD/CAM, DXF and laser cut... or at least some kind of chassis punch. Deburring via some kind of machine would be good too.

I've deliberately left the side plates completely clear - no piercing. This is aesthetic, I've yet to see a bike with an exposed battery looking good.

I got curious and weighed the collection on my kitchen scales - they came in at 1540 g, total. I haven't weighed the former airbox yet.