Generator

[DarcyG]

Before I attempted to start my motor for the first time I have been building up oil pressure by simply turning the motor over with the starter motor. All was going well and then I need that the fan blades stopped turning. I checked tension, re tensioned to be sure but still the same problem.

Then I notice that the generator wheel was not turning square but had developed a wobble.

Before I start pulling things apart has anyone any idea what this could be - could the shaft have bent?

[DarcyG]

Sorry to trouble everyone problem solved. It is late in the day, I thought I would have another closer look contemplating what I would need to pull it down. Then I saw it - the nut on the pulley was loose, not by much, but enough, why or how I don't know. But I tightened it and all is working. Tomorrow I will put a new spring washer in place and possibly a locking washer.

[jeans_old_man]

The pulley should be keyed in position by a small, half-moon shaped, Woodruff key and held on by a 3/8 BSF castle nut and split pin. If the engine has been running with this nut loose, the chances are that the keyway - and the one under the chain sprocket - will be damaged.

You can remove the shaft to examine it without dismantling the engine. Take off the castle nut and the plain washer and remove the pulley. Retrieve the Woodruff key. Remove the dynamo leaving the distributor and housing in place. The shaft can be pushed out and the chain sprocket will be held in place supported by the bronze bearing. Insert a rod from the front to prevent the 'mexican hat' falling down and be careful not to lose the second Woodruff key - the one for the chain sprocket.

If the keyways are damaged beyond repair try Hardwicks for a replacemnt. It might be worth replacing the distributor gear at the same time. After reassembly you will probably need to set the ignition timing unless you have been lucky enough to engage the distributor drive gear in its original position.

Good luck!

[darcy]

Thanks, no the engine was only turning over on the starter so hopefully no major damage BUT NO SPLIT PIN. That explains what happened and thankfully, at this stage. I will go down shortly and check the shaft further, it is an original shaft so the hole should be there.

Just as well I posted, thanks.

[DarcyG]

I just checked, when the unit was restored they did not put a castellated nut on the shaft with split pin, only a normal nut and spring washer which obviously does not work. Looking at the drawings above and an original photo of the unit pre-restoration it is quite clear what should be there.

Now all I need to do is hope I have a suitable nut as COVID does not allow me to visit my normal supplier. But I am pretty sure I have one, or could make one.

I love this photo with the old shoe heels used to seat the radiator. If it worked you did it.