Project XT250

Last updated: Sat, 20 Nov 2010 04:06:00 GMT

The missus kindly volunteered to wrangle the kids this afternoon for a few hours, so I got me some carb rebuilding done.

I bought a Keyster (*snigger*) carb rebuild kit a while back on eBay, for US$25. It's at the better end of your pattern fare -- decent quality, nearly all the parts, no extra bits to make you worry you've put it together wrong. In fact, it was a better match to my carb than the Clymer manual.

Some previous owner had given the bike the world's worst and most cursory rattle-can respray; had, quite literally, just pulled the tank, partially covered the wheels and instrument cluster, and sprayed the general area black. There's flashover everywhere: wheel rims, cables, fork legs, you name it. Including the carburetor. So, job number one was stripping the paint.

Luckily, I've got some sort of horrific cocktail of solvents and acids in an aerosol can, labelled "gasket remover". I believe it may have been Ronald Shusett's inspiration for the creature's blood in Alien. That stuff removes everything, including skin. So, minor chemical burns were the order of the day. Then much degreasing -- the carb's full of soapy deposits, and some external moving parts have been questionably greased with glue. Finally, some brass wire brushing, before another good dosing of carb cleaner to degrease and make good.

Well, it looks old. It's got wossit... patina. It's an aesthetic thing, honest -- who wants an old bike that looks new? Well, that's what I'll tell people anyway. Trust me: it's a lot nicer than it was. And all of the important parts have been serviced or replaced, seals and gaskets are new and the accelerator pump now works...

Which will prove problematic some time down the line; the pump mechanism was previously missing a spring, meaning that it was previously not being actuated when the throttle cam was rotated. So there was no adjustment to record when it was disassembled. Luckily, my large bucket of Bits I Never Throw Out contained a spring of exactly the right dimensions, so the pump's whole again. Unfortunately, the Clymer manual has no guidance on adjusting the pump. It doesn't even give any clues for reassembly; relying on that old standard, "assembly is the reverse of disassembly."

Answers on a postcard...