A Bit Off Topic KTM 504 crank

[Bill Campbell]

Is there anybody out there with experience of rebuilding the crank for a 504 4 stroke. There is an oil slinger attached to the crank and I don't know what to do with this when separating the lobes.

Cheers
Bill

[Mike Rosso]

Bill there's nothing you need to do as it can stay in place when separating the crankshaft when replacing the connecting rod. At KTM we had "crank" separating plates made by Dane Leimbach for some and earlier by either Ted or maybe Dane too. The crank plates had a "U" shape cutout and then stepped to accept the shape of the inside crankshaft flywheels. This way the crankshaft laid flat and you then pushed one side flywheel off (not the big end pin first). The you flipped the other flywheel half over and then pushed the pin out of the flywheel. A trick I learned was you could very carefully use a oxy/acetylene cutting torch and from the big end connecting rod pin's center cut a thin line outward to stress relieve the pin's tension and the pin was very easy to remove at this point. Surprisingly I learned that the press fit tolerance of pin to the flywheel would not transfer the heat from the cutting torch quick enough and it would avoid damaging the flywheel as you got close to the outer edge of the pin. Also you need to remove the main bearings to do this correctly. You can access the big end pin on the oil sling disc with a smaller pin like a piston wrist pin to push the big end pin out of the oil sling disc side. If I can find photos of the crank separating plates, I'll post them.     

[Bill Campbell]

Thanks Mike. this was for a friend of mine who has a couple of 504s and was getting a new rod in the crank. It has been done but your information gives him piece of mind in the process. It will be handy for the future for him and myself as i have one as well. Keep adding your interesting snippets to social media.