So we've had a look into why my CG is playing up and its looks like the woodruff key has torn through the crank shaft, so basically the timing is right out making it impossible to get it started. Now the reason I've came here to tell you this is, I was wondering if anyone on here is capable of repairing the chunk that is missing out of the crank shaft for me, or if anyone has done this before like welding it and reshaping I could do with any advice at all... After looking over it if this can't be done we are going to have to replace the crank shaft which means a whole engine rebuild, which I'd love to avoid. Any help would be appreciated
The metal can be rebuilt, but would require removing the crankshaft, machining the section of the woodruff key down, building it back up with metal spray or similar, before final machining back to the required diameter and cutting the key slot. Depending on where the key is located, there may be a need to heat treat the final finished product. Ignoring the cost of heat treatment alone, I would imagine the cost for machine the crankshaft alone would cost more than a replacement. Cheapest option may be to source a secondhand engine. Can anyone else suggest an even cheaper 'fix' (not bodge)?
We've looked at replacements and its about 70-100 pounds its just the labour involved in doing it i was hoping it could be done while still in the engine hahaha saves a full day taking it apart and rebuilding it, id much rather buy a new one if it came to that.
Get another engine and change it out. Cheaper that replacing the crank. It's not that difficult. Believe you're in Manchester. Can lend a hand one Saturday.
im thinking get a new engine myself, i might try find a CDI one with an electric start if im lucky, will make things a hell of a lot easier im just a bit weary of buying engines as you will never know whats in them ready to break. Thanks for the thought of lending a hand, unfortunatley cant afford it till jan maybe december sooo its going away for the winter now i think.
If you like it may be possible to form a decent repair with a new woodruff key and some epoxy putty (J-B Weld stuff) to fix it in place in the keyway. The LH of the keyway was still intact so it should work. What looks to have happened is the tapers on the flywheel and the crank don't match up like they should and it didn't hold up under load from the engine, they key tried to stop it from spinning and it failed and took the crank with it. I did detect some high spots as I was trying the flywheel's fit on the crank the other day. It would be worth lapping them together with grinding paste to match them back up again, similar to what is done with valves in the cylinder head. I still have a tub of the paste from when I whipped the head off to replace the gaskets and do the valves and oil seals.
