bertsmobile1
Lawn Royalty
- Joined
- Nov 29, 2014
- Threads
- 64
- Messages
- 24,702
Low oil and in particular low oil running along a slope can deprive the top bush of oil so it runs dry for a couple of seconds then the aluminium rips out and welds to the steel crankshaft.
It is a common problem particularly on gravity fed engies as people mow carb side down which means it is pump side up
Usually we would pull the engine, remove the crankshaft degrease it then do a cold HCl dip or hot NAOH dip to chemically remove the aluminium then a polish with a scotch brite pad to clean up any remaining roughness ( NO ABRASIVES TO BE USED )
Then go up one grade thicker oil
It is a common problem particularly on gravity fed engies as people mow carb side down which means it is pump side up
Usually we would pull the engine, remove the crankshaft degrease it then do a cold HCl dip or hot NAOH dip to chemically remove the aluminium then a polish with a scotch brite pad to clean up any remaining roughness ( NO ABRASIVES TO BE USED )
Then go up one grade thicker oil