Wednesday, 24 May 2017

The other XS Triple Sidecar - fixing carbs and electrickery

Weirdly enough, ever since I bought the 750 the Mikuni Mik1 carbs have been leaking on #1. Three new floats and float valves couldn't cure it until I bought a scrap carburettor from a friend and tried using the original float valves with the protective shields installed. Turns out, that the bike must have been parked on the sidestand for a long time and now petrol dissolves the residues and they clog up the float valves. After taking the carbs off a two more times now the float bowls look clean and the carb has stopped leaking. The residue itself was interesting: it looked a lot like some fuel tank liner or something along those lines as it was really flaky and not the usual rust-gunk.



A bit of re-wiring on the sidecar brought both the front and rear-lights back to life.



And this is a special for all those who want to know how to distinguish 64hp heads from the later 74hp heads. (The one shown below is an 850 head though!)

64hp-head 

850 head
... and except for fitting the (not yet delivered) 16" sidecar tyre, the other XS Triple Sidecar is pretty much ready for a new owner.

She does sound mighty tasty, mind you (carbs sync'ed and floats adjusted):


Saturday, 20 May 2017

The XS Triple Sidecar - cracking locks and getting small stuff done

There's not a whole lot a (petrol-engined) bike needs to work properly: spark and fuel at the right time and mix in a bit of air and you're golden. That being said, I've had to work on more than one bike in the past where the sparkplug wires were a straight mess and the reason for a weak or intermittent spark and subsequently the reason behind lots of (unnecessary) headscratching.
Now as the XS-Triple-Sidecar is not meant to be some sort of show-pony, but a daily driver, it only made sense to get some fine silicone sparkplug wire with moulded on caps as these have withstood the elements quite well in the past.

And guess what, even thought these coils didn't show any signs of it yet, there was some rust on the core already.


When swapping out the sparkplug cables always make sure you keep the old ferule as that's what's going to hold the new cable in place.


I do admit, that the red colour is a tad flashy, but then again my local bike shop didn't stock them in black and I absolutely wanted the one-piece-cables for reasons of reliability.



A bit of T-piece-art or how to feed three inlets with only two petcocks.


And lastly onto the matter of the lock. I don't have the key to this petrol cap and even if I did, I only want to carry one key per bike. So I took the lock apart, removed the locking tabs, cleaned everything up (yes, I do that sometimes) and reassembled everything.





Testing the petrol cap with my new "universal" key a.k.a. a flatblade screwdriver.


Throttle cables and the missing upper part of the fuel lines next and then it should be pretty close to firing it up with the VM36es.

Wednesday, 17 May 2017

The other XS Triple Sidecar - how to convert to points and...

... it's running.

The difference between genius and stupid ideas is often just a point of view thing. Most people I know wouldn't want to fit a sidecar to a motorcycle, I think it's absolutely grand. Same goes for XS750/850 riders and points ignitions. Generally everybody wants to convert to electronic ignition for the apparent benefits, as such there's quite a few explanations out there on how to convert to electronic ignition on a 750 loom, but not a single one on how to go the other way. Well, now there is.

That's what I started with at 8:30 in the morning in my dad's garage. 



 The 4-pin-connector of the points-ignition on the engine.


 And its 6-pin counterpart on the 850 loom.



Pinned out the 4-pin-connector on an old loom.


And did the same with the 6-pin-connector on the 850 loom. As the looms strictly speaking work the same, it's no big deal, as you just have extra switched +12V and ground wires and the other four (3 coils and neutral) are the same.


Insulate the two open terminals and that's the conversion done. As easy as that.


Getting the old r/r-unit off, without removing the battery tray is next to impossible so Markus fitted the new one inside the battery tray, because the space was empty anyway as he used a car-battery in the sidecar.



While we were at it, made some new ground wires, because you can never have too good ground on a bike. 


The old BOSCH-headlight I used is a tad smaller, so fitting everything inside was going to be a bit of a challenge, especially as it came off my XS750 and that mostly used bullet-connectors, where as the 850 loom has got a lot more multi-connectors, which are super for wiring up, but a bit of a pain space-wise.


Carbs are in.

Quick oilchange, before startup as I had to take off the filter housing anyway, because of the oilcooler still missing on the bike.


That's the level of clean I want to see in a filter housing (and an oilpan), but you know that already.


Looking pretty good with all the lights and stuff installed. Ready to roll.


That was quite literally the second startup of the 750, just cranked it over once before to make sure I have oilpressure etc and it fired right up.


And that's my hairy arse on the first testride right out of the gates at my dad's humble domicile ...


... aaaaand coming back. (I've repeated that process a few times - it's pretty awesome!)


What you can't see in the videos: a 25kg (50 pound) bag of sand on the seat as the sidecar is really light and just loves to climb.

So what's left to do: Get a new 16" sidecar tyre, dial in the carbs, tighten up the exhaust and then find someone who's after a nice learner sidecar. It's all in the (German) papers, so if sidecars are your thing, drop me a line and we'll work something out.

Sunday, 14 May 2017

The XS Triple Sidecar - VM carbs

Having fed my engine-swap-fetish for a while, I've finally started to make some progress on the XS Triple sidecar. One of the things, which annoyed me in the past were those pesky CV carbs. Don't get me wrong: They do work fine, but ever since I felt the difference on my TR1, I knew I wanted MOAAAR.

Bring on VM36es out of a snowmobile. A while ago I cleaned them in an ultrasonic bath and may I say: They came out quite clean. 


The stock jetting was obviously for a two-stroke, so I've rather conservatively jetted them to #17, #145. That's what I ran my Mikuni CV-carbs out of a Triumph years ago and it seemed to be quite alright. Or let's put it this way, it should at the very least fire up with this setup. 


New breather tubes fitted. The stock ones were hard as a coffin nail and like glass. This time I used some silicone hose intended for usage in a chemistry lab, which was over the due date. (It's mad where you can find TÜV-regulations...) Why put on breather tubes anyway? Well, they are directly connected to the float bowl and the tubes prevent/limit dust/water ingress into the float chambers, so they actually are quite useful. 


They are a bit of a snug fit with the breather tubes routed to the sides but it is doable. 



Really curious on how they will perform, even though this still may be a few days away as I have to re-wire the XS for the 850 engine.

Friday, 12 May 2017

Exhaust-building - Mk.7 2in1 exhaust

There's a German pro-verb, that Spring will occasionally bring in something new. I've built, modelled after the equal-header-length 2in2 Mk.7, a 2in1 with headers of the same length. This one is meant to go on a XV750 and I am really, really curious to see, whether the smaller header tube diameter will yield the benefits in low-end torque.

It's not exactly the first XV-exhaust I've built, but I decided to change and try out a few things, based on what worked on the Guzzi and what gave me headaches in the past.

Firstly I had bigger flanges cut, which still don't do away with the need to use exhaust gaskets, but will seal a lot better as they are a snug fit into the head and it cures potential misalignment and shifting during welding.



I used an old lathe chuck this time to have the rings sit REALLY perpendicular to the tube.



The second added bonus of doing small inserts for the head, it's a lot easier to measure the downtubes as you have a fixed datum to work from. 


Tube fitment is the one big thing when TIG-welding. Every minute you spend on fitting up the parts will come back to you at least double, when welding. 



I admit I have been a tad too careful with how much I cut out on the inside...


... which meant attacking the innards with a carbide burr on a die-grinder for approx 90 minutes and then buffing everything up with a mini flapper wheel. 


The time when parts take shape. 



And that's what I ended up with: once on the bike 


... and on the bench.


But don't worry, this one is not meant to go on my everyday TR1, but on a different bike... Actually I plan to re-do the Mk.7 from the everyday TR1 in Summer as I've improved the design in various areas (mostly fabrication-wise and a bit in fitment, I think) and I need a second Mk.7 anyway to be used with the supercharged TR1...