This is my father’s Scott Squirrel from 1956. He’s done tens of thousands of miles on it over 30 odd years of ownership. He absolutely loves the thing, probably more than he loves anything else in the entire world. Unfortunately the engine ate one of its piston rings, so he took it to bits. Since then he’s fallen victim to Alzheimer’s and the job of fixing it now falls on me.
I was presented with a pile of parts thrown on a bench, along with every worn out spare part he ever had for all the bikes he ever owned (my father never throws anything away no matter how knackered it is) and he has no idea what belongs to what or how they all go together. What passes for a workshop manual consists of a pile of A4 papers 5 inches thick (I’m not kidding), which amount to every letter, article or random musings on any Scott related technical topic stretching back to 1908. Most of which appears to be a photocopy of a photocopy of a clue to the Times cryptic crossword. Oh joy.
First the barrels needed repairing as there was a big score down one of them from the broken piston ring and a large crack in the ports. That had to be laser welded by a specialist in Birmingham. Then we had to have the barrels rebored and two new pistons made. That took months as apparently you can count the number of people in the country capable of doing it on the fingers of an Agincourt salute.
Eventually we got the parts but of course nothing fits together. The pistons have to be fitted to the con rods with a file, either by slimming down the little end bush or relieving the piston to suit. This is a pig of a job because the end float on the crank is largely set by the position of the piston on the con rod. The crank is overhung, supported in the middle on two bearing and consists of a central flywheel and two half cranks pressed together on taper fit journals. The big ends then hang off the end of each crank with no outer support. An utterly crap design that never seems to go back together in the same position twice.
The gudgeon pins are a press fit in the pistons so you have to use a special puller, which I had to make. They seize up if you don’t get it right and it’s darned difficult to measure anything as everything changes each time you press the thing apart. Once you’ve done that you need to balance the rods and pistons which involves grinding out material from any place you think you can get away with it.
Then you can put the engine back together. I must have done this at least 3 times getting all the parts to fit together in the first place. You have to modify all the gaskets because no two Scott’s are the same and all the parts come in one size fits none. After months and months of ball ache after ball ache I thought I was finally getting to the end of it when I got into the garage today and find the head gasket is leaking and the antifreeze has stripped the paint off the barrels. So I pull it apart, again, strip the barrels down again ready for painting, again, and take a look at the cylinder head. It has a 10 thou bow in it, apparently a known hazard of taking Scott engines apart. Who knew?
This is a huge problem because the cylinder head has a brass tube pressed through it for the thermo-siphon cooling system which has to be removed prior to skimming. I have no idea how this is going to come out without wrecking something. I may have to destroy it and make a replacement. Knowing my luck, skimming the head will mean the compression ratio will be too high and the pistons will hit the top.
I don’t think I’ve ever known a motorcycle to fight so hard to avoid being fixed as this one. I am beginning to thoroughly despise the thing.