Tightening the big nuts

Previously John Tickell wrote:

I've messed on with motorcycles now for roughly 50 years and got by dealing with the above by using long spanners and big hammers, not good engineering eh.

The three that mainly concern me are the crank, gearbox and clutch Centre nuts. Jamming something between the chain and sprocket, whilst it works, has never seemed a very nice engineering solution.

I know the engine can be locked with a bar through the small end but what if the engine is complete? and standing on the back brake enables the gearbox/clutch nuts to be tightened, again not ideal.

I now have the time, retired, if need be to make up/fabricate suitable locking devices.

How have you overcome these problems? John

I use a clutch locking plate bolted to a long steel bar via spacers

A chain wrench should hold the engine & gearbox sprockets. Can be made from a short piece of solid bar or strong tube, bored at one end so that a length of old chain of suitable size can be passed through. On the other end you need a tommy bar. Mine is made from a substantial old plug spanner, see pic.

I have belt drive so jamming the chain so not an option. I like Christopher have a clutch locking tool that in my case i have welded an old socket to so a ratchet or long Tee bar can be used to hold the clutch stationery. When there was nothing on the crank shaft as i rebuilt the engine on the bench i fitted the old triplex sprocket and used a 36 inch set of stillsons to hold the sprocket to tighten the LH nut on other end of shaft after fitting pistons barrels an setting cam timing.

I have read of some mechanicspositioning the piston at the bottom of the compression stroke and feeding in through the plug hole, a length of cord. This will prevent the piston from reaching T.D.C., I have never tried this, though itsounds too simple an idea to discard.

Paul

Previously Paul Knapp wrote:

I have read of some mechanicspositioning the piston at the bottom of the compression stroke and feeding in through the plug hole, a length of cord. This will prevent the piston from reaching T.D.C., I have never tried this, though itsounds too simple an idea to discard.

Paul

That's how I do it, get some nylon rope that will fit through the plug hole and melt the ends so it does not fray. Easy to carry and easy to do even on the roadside. Don't forget you must be before compression so the valves are closed and I normally feed the rope in with the piston just before midway on the way up to TDC.

Mark

Put the gearbox in high gear and then apply the brake. Much better mechanical advantage. Then use your torque wrench.

Mike