If you ever need to take the flywheel off a Grasshopper, you might like to know that, at least where the early machines are concerned, there’s a little more to it than meets the eye.
If your machine’s serial number is 45655 or higher, the flywheel comes off as you would expect – you just unscrew the screw which obviously locks it to the shaft, and pull the flywheel off. If you keep unscrewing that screw and take it out, you will find that it looks like the top one in this picture …
Also shown in that shot is the two-part affair used on machines up to serial number 45654, and that consists of a “flywheel screw” (the long bit) and a “flywheeel pointed pin”. When you unscrew the flywheel screw, it comes out just like you’d expect, but the pointed pin doesn’t, and it’s that which will probably prevent you from being able to slide the flywheel off the shaft.
On the later Grasshoppers, the point on the end of the one-piece screw locates in the groove cut in the shaft and thereby locks flywheel to it. But on the early machines, it’s the flywheel pointed pin (the short bit) which engages in the slot. The flywheel screw only applies pressure to the pointed pin and locks it all in place.
Why they did it like that is a moot point, but whatever. Here we see the “inside” of the early-type flywheel with the flywheel screw unscrewed as far as it unscrews. Note that the point of the flywheel pointed pin is still projecting through the bore of the flywheel, so if that flywheel was still in place on the shaft which is visible behind it in that picture, the point of the pin would still be located in the groove.
In theory, you should be able to take out the screw of an early flywheel, rotate it until the screw hole is at bottom dead centre, then either tap or jiggle the flywheel, whereupon the flywheel pointed pin will obligingly fall out and you’ll be able to pull the flywheel off.
In practice they tend to stick (or at least two I’ve met did), so flywheel removal on a Series One Grasshopper can become a rather protracted performance involving penetrating oil and patience. Maybe even a small gear-puller too if you can lay your hands on one.
The good news is that reassembly’s a doddle with either type, and is just a case of making sure that as you slide the flywheel onto the (lightly oiled) end of the shaft, the screw hole is aligned with the slot. It helps to have the slot at top dead centre, and a small torch is handy too.
If your machine’s one of the early ones, don’t forget to pop the pin back in its hole first, and then keep the flywheel hole-uppermost until you’re sure it’s all back together properly …