Sunday 4 November 2018

The XS Triple Sidecar - alternator swap (and various other fixes along the way)

To be fair, the last time I worked on the old girl was approx. 4 months ago. Then I was left stranded twice with an empty battery, which led me to investigate into the cause of that mishap. Turns out, it wasn't the reg/rec-unit (well, now I have a spare), but actually the alternator being fried.
Contrary to my fears, it was actually dead simple to get a new alternator. Removing the old one was not. But if it would have been, that wouldn't have made such a nice post, would it? 😏

As per the norm, the sidecar had to come off, in order to make access to the alternator easier.

Unlike on my other bikes, the alternator is not oil-cooled, so it should have been just a quick job of taking the cover off and that'll be it – I thought.

Unfortunately some numpty (me) had routed the alternator cables through what seemed like a suitable groove in the back of the engine cases. This meant that now the engine had to be lifted as I couldn't pull the cables with the plugs through.

Well, greasing various bolts and axles will save me from a lot of hassle at some other date, right?

From that point on the whole exercise was fairly straightforward and just meant replacing the alternator and then rerouting the cables correctly and greasing up the connectors. 

And charging again: almost 14V at a bit over idle and stops nicely at 14.4V. On top of that, I was finally able to put my new toy (a clamp-on multimeter) to use. At mid rpm, the alternator pushes out around 6A, at max. rpm almost 10A. Sort of explains, why the old battery gassed out every now and then.

Ka-Boom. Looks cool, eh? Trust me the neighbours love me. 😅 Unfortunately this was the first indicator of one of the coils packing in. Luckily about two years ago, some guy in Vienna parted out his XS850 and so along with an engine, I also bought various bits that I thought might come in handy down the line, e.g. coils, a spare CDI and various other this 'n' that's. 

As I needed some time to work this niggle out, I turned my attention to another one of those problem areas. For some odd reason, the rear brake shaft tends to seize in the frame of those old XS-Triples. Mine was no exception and as such the only sensible solution was to fit a grease nipple. And as you can see in the picture below, even though I re-greased the shaft about a year ago and I was rather generous, mind you, it didn't prevent the build-up of rust.

 Now the stock green tach and speedo are dead cool, but unfortunately at least on my old girl, the speedo had decided to call it a day and get stuck at the highest speed driven and then come back down to zero very, very slowly over the next few minutes. (Gives the phrase: "Looks fast, when parked" a completely new meaning...)

As I am not made from money, I didn't have a genuine XS850 speedo, but only an old XS400 unit from the old RatRacer XS400. Though this only had a provision for a single bulb to back-light it. So a second 13mmwas necessary. Now, if you're good at maths you'll notice, that there are actually three bulb-sized holes in the back. Let's just say I found out, that the hole on the left is cool 'n' all, but it's somewhat less likely that I do 200kph than the other end of the spectrum of the range.

So I had found' out about the dead coil and the bike fired up again, but based on my experiences with the 38mm flatslides and the fact that the old girl was running dead lean at low rpm, switched to running dead rich at mid range only to fall on its face again at max. rpm, I decided to take the air-jets (1.0mm) out and give the bike a test-run without them.

Whoops. The bike was a bit hard to start, but then rev'ed like mad and well... ran a tad lean. By now the pilots have been increased by 12.5 points, mains by 20 and the needle raised 1.5 notches (it uses a funky system of notches and shims to fine-tune the needle) and we're starting to get somewhere. 

Give it another two-and-a-half hours, even larger pilots and mains (#40, #138, needle on the middle setting (no shims), mixture 3 turns out) and a bit more ignition advance and all of a sudden the old girl finally runs and idles like it should.

And lastly while cleaning up the workshop I found some old breather hose I had originally bought for the Everyday TR1 and which was *just* long enough to relocate the breather to a spot where riding in bad weather will not allow water to get into the engine via the breather. 

A bit more tweaking might be necessary on the carbs, but now we're definitely getting somewhere and for the first time, since I've had the flatslides on, it will start just fine when hot.

No comments:

Post a Comment