I still have a few jobs to do on the scooter, and I plan to update the blog with more details (and some pictures) in the next few days.

I have some more news, I have a new project! I bought a Suzuki GN250, 4 stroke single chopper style bike. I bought it as a pile of parts and it easily went in the car like that. Literally every part was separated (the engine was in one lump, but the carb, exhaust and so on were not attached, and the frame was so light with nothing attached that you could pick it up with one hand easily). I will write about and show photos of this very soon too.

I have taken the handlebars, instruments and panels all off the front end in preparation for cleaning and repacking the steering head bearings with grease, when I noticed that in the accident this bike had, the steering must have forcefully been jammed from neutral (straight ahead) to the right hand side, because the collar that sets the steering limits had been bashed and had flared out causing the grinding and squeaking, I filed this to the correct shape, applied rust remedy and it is now perfect.

I have also tried to rejuvenate the rear brake cable with the funnel of blu-tack and thin oil trick. This is underway at the moment, and may work fine, but I also noticed a while ago that a section of the rear brake cable had been caught in between the back wheel and the transmission
casing. I have inspected this further today and noticed that it’s ripped the outer sheath off and has mangled and rusted the steel coil inside slightyl. I am about to research prices for new cables, but I still have hope for this one. It’s a shame, the inner seems fine, just a little rust-stained.

My new transmission rollers arrived a couple of days ago, so I am almost ready to fit those, after these couple of jobs.

I decided to brush off the bits of corrosion that I could see, then take the wheel to the bike shop, then get them to check the tyre for punctures to be sure. They suggested putting an inner tube in the wheel if the tyre was okay, which was an idea I liked, but I didn’t like the idea that the wheel was still corroded and half-painted. I decided to buy the inner tube, and to take it home to do myself. This gave me a chance to strip and repaint the wheel properly inside and out.

Here is the wheel before stripping. You can see corrosion inside and out of the rim, and also around the valve. Not to mention the rusty glazed brake drum. No wonder that back brake was sticking on.

Here is the other side of the wheel after stripping the paint off. I used normal paint stripper from a tin, a screwdriver and a wire brush to do this, and it took about 90 minutes to do it thoroughly. And I didn’t burn myself once!

Here is the same wheel after two brushed-on coats of “Hammerite Special Metals Primer”, which is a water based etch primer for non-ferrous metals, aluminium, brass, etc:

And finally after 3-4 coats of satin black  (acrylic from a spray can):

Just waiting for the paint to harden fully before I manhandle the tyre and tube back on. I know it will probably work without a tube now the corrosion is taken care of, but I didn’t buy a replacement valve, so I’ll stick to the idea of using a tube. When the tyre is eventually replaced, it can be replaced normally, of course.

• Clean and refit carb
• Replace reed valve block (including adjusting length of reeds, they wouldn’t open..
• Weld up a new exhaust mounting bracket, and fit exhaust
• Disassemble transmission, clean cones, check belt, check rollers
• Rollers were heavily worn, so ordered replacment rollers
• Replace oil filler cap
• Determined that the rear tyre needed repairing/replacing, it kept leaking air every time I pumped it up

Here are some pictures, you’ll notice the rear wheel is off at the moment, as the tyre needs looking at. You can also see the new/old exhaust now. From the side:

And here is the bike from the front:

And finally, the bracket I made for the exhaust, the original lugs had snapped off, so I filed a flat on the casing, tapped a couple of metric holes, and welded up a steel bracket to hold the exhaust:

As I said, the bike starts nicely now, with the kickstarter only at the moment.

The bike was easy to collect, because it was bought from a chap who only lives about 1 mile away from me, and because I’m looking after my dad’s trailer for now, which came in handy. I took ownership of the bike at about 8pm on Monday 23rd August 2010. It didn’t look too pretty, the transmission cover was off, most of the panels were off, the petrol tank was loose, the carb was hanging by it’s fuel and throttle lines, the steering creaked, the entire exhaust and mounting points for it were missing, etc. The rear brake cable had also been jammed between the transmission and the rear wheel, so it had to be carried onto the trailer. This bike has been off road for around 3 years, so there is a reasonable amount of rust on the single front fork and the underneath around the frame and centre stand. I think all of it is minor though, and it’s coming off quite readily just brushing it off by hand.

The bike had been owned by a young chap that presumably didn’t know a lot about looking after mechanical things, he’d tried taking this one to bits to fix something (who knows what?), presumably not been able to fix it and then left it disassembled. Although, I saw that he’d got himself a new moped that was almost the same, which is a good sign, apparently even if one goes wrong, it’s worth getting another one!

I managed to turn the engine over by hand, which shows that the engine wasn’t seized, and luckily there was reasonable compression for a 50cc bike. This is the main factor for me, I really don’t want to have to get barrels reworked, or buy new piston/bore kits if I don’t have to. The goal here is not for this to be a money sink, it’s to learn a bit more about the practical side of mechanics, and to get a broken bike recycled and made into a working bike as cheaply as possible. I paid £30 for this bike, and I have seen decent bikes of the same age sell for £500 or so.

I spent about 3/4 of a day on it yesterday (24th Aug 2010), and got the following done:

• Remove cable from between rear wheel and transmission, loosen back brake, find cable is seriously gummed or rusted up, but salvageable.
• Clean, re-grease and reassemble kickstart and electric start mechanisms
• Bang dust out of centrifugal clutch, while it was exposed
• Check battery electrolyte levels, clean terminals and charge (it had 1V of power to start with)
• Check operation of vacuum petrol tap, condition of vacuum hose (good)
• Quick clean of carburettor jets and reattach carb (pilot jet was blocked, float boal full of grit and grime)
• Drain fuel from tank and float bowl, and replace with fresh 95 RON unleaded (correct for this bike).
• Remove broken exhaust flange (noticed 1 stud missing, and a tiny part of the exhaust mounting surround is broken away, but it should still make a good seal with a new gasket and replacing the missing stud).
• Remove remaining rear end bodywork (cracked and scuffed and will need fibreglass repair)
• Pump up flat rear tyre (this will determine if there’s a puncture or not)
• Clean and set gap on spark plug
• Apply WD-40 to the lock mechanisms until they work
• Test operation of the starter motor circuit including starter button, ignition, starter relay (works)
• Test operation of the starter motor (doesn’t work -but it’s dismantleable, and there’s a kickstart for now, anyway).
• Tested operation of immobiliser aerial/unit
• Tested other electrical items all the following worked: starter switch and relay, ignition switch, immobiliser, immobiliser aerial, and warning LED, fuel level sender and gauge, horn + horn switch, turn signal relay, front turn signals, oil level LED
• Tested headlights (didn’t work, but they may only work when the engine is running).
• Check condition of reed valves (reeds didn’t lie flat, even when turned over, because the block facing isn’t flat, I’ve ordered a new one: £10.98 including delivery)

Luckily, I found a manual online showing the wiring diagram for the bike (I couldn’t get a spark to start with, which prompted the electrical testing), I’ve been cleaning connections and battery terminals as I look at them, and after doing this for a while, I managed to get a reliable, strong spark.

The importing testing went as follows:

• Tested compression (8.5 bar or 120 PSI roughly, no major problems there).
• Tested spark: Strong, reliable spark
• Tested starting: No luck. I couldn’t tell to begin with whether it was a mix of 2-stroke oil and fuel getting on the plug, but now I think it’s just oil. There are a few other reasons that the bike would be hard to start and run: No back pressure exists from exhaust, also not a great seal from the poor reed valve block. The main reason though is that there is probably no fuel coming through the carb.

Clearly next job is a proper clean of the carb. Also, I need to replace the exhaust and reed valve block. The exhaust is ordered now too: £33.99 including delivery, but it will be a week or more before I get it.

Here is a final list for this post, it shows current costs so far. I’m recording everything here apart from ordinary consumables (just fuel and oil so far). All prices include delivery.

• Bike £30
• Manual £7.49
• 2nd hand exhaust £33.99
• Reed valve block £10.98

Total spend: £82.46

Pics and more to follow in the next day or two.

Back to the difficulties I’m having though though; replacing fonts is a slightly more complicated task than I’d realised. The nesting of various text elements  (e.g. text and tspan elements), and the two different ways of applying styles to these text-ish elements makes it difficult to know how many replacements are being made. Of course it’s easy to just count all replacements, but the number of text styles that needed to be replaced will be possibly more than twice the number of actual elements affected. Here’s a concrete example, because I don’t quite believe in the explanation I just wrote:

1. Open inkscape 0.47 on Ubuntu 10.10 Alpha 3
2. Click anywhere with the text tool and type in: Hello<press return>World.
3. Press Ctrl-A, change the font to Bitstream Charter.

If you do this simple sequence of steps, you will probably (and understandably) think that you have made a single text element. If you are the skeptical kind (like me), you might even think that you had made two text elements. You’ve actually made three. There are two tspan elements nested inside a text element.

So, you may now thinking, well, just count the one parent element then and style the two inner elements. But all three are style-able. And all three are style-able in two different ways. I haven’t found any documentation to explain inheritance or precedence of styles between the different elements, or between the two (potentially) conflicting style attributes themselves, one of which is unique to inkscape, and doesn’t appear anywhere in the SVG spec. The two style attributes are ” font-family” and “-inkscape-font-specification”, and they can both apply to parents and children.

We now have potentially six font styles to replace for two lines of text from one click of the text tool. It just so happens (for me) that inkscape sets the font styles in the following ways: The text element has just a font-family, and the tspans have both the -inkscape-font-specification and the font-family. So there are five to deal with, but of course it’s the potential number that matters to my code. I believe that my tool does replace all five (or six) correctly, but you can see it’s quite difficult to usefully send a message to the user such as “Replaced that font in X places”, for now, users will have to live with “Replaced all instances of that font successfully” or similar.

Note: I realise 0.48 has just come out, and there are internal improvements to text handling, but I haven’t had a chance to look at these yet. Also – I know I could probably nag the inkscape-devel list and ask for some guidelines about the different style attributes, and rules about applying them to the elements, but again haven’t yet had a chance.

It’s probably very rough and ready at the moment, but it should be useful.  I plan to change the way the actual font is replaced, because it’s conceivable that it could break as is, but I haven’t had it do so.

Leave me some feedback if you have any problems. Once it’s had a fair bit of testing, I might try to get this one entered into the inkscape repository too.

So – here’s how you use it:

1. Download the latest replace_font version and unzip it into your inkscape extensions directory
2. Open your drawing in inkscape, preferably one that has some text elements, of course.
3. Select Text->Replace Font from the Extensions menu
4. Enter the font name that you want to find, e.g. Calibri or Times New Roman
5. Enter the font name that you’d like to replace it with, e.g. Sans or Helvetica
6. Press Apply

Enjoy!

Edit:

There were a few bug in this extension, as pointed out by su-v from #inkscape:

1. Not all fonts were being replaced, because sometimes the font styling was attached to a text element, not a tspan.
2. tspan elements without style attributes were causing the extension to crash
3. Some fonts (such as Arial Narrow) were being incorrectly (partially) replaced by searches such as “Arial”.
4. Fonts in flowed text regions weren’t being replaced at all.

The link above in the original instructions has been updated to point to a new zip file including a fixed version of the extension, along with a couple of new features. Please let me know if you run into any other bugs!

I’m sure it will need more work if and when more people start testing it, but it should be usable as is. Please give it a try and feel free to leave any feedback.

It would be nice to one day see it as part of inkscape proper, but I don’t know the process involved (or if there’s even any demand for this extension – there are similar but slightly different extensions floating around).

So – here’s how you use it:

1. Download the latest guillotine version, and unzip it into your inkscape extensions directory
2. Open your drawing in inkscape.
3. Drag some vertical and horizontal guides onto your drawing
4. Select Export->Guillotine from the Inkscape menu
5. Enter a directory name and image base name for output (e.g. output will become output1.png, output2.png, etc.)
6. (optional) If you’ve previously exported the drawing, you can tick the box to use export hints as the output values.
7. Press Apply

Enjoy!