RE: Neoprene, Tygon, and Viton UV Resistance
Richard,
It is just that you need to periodically check the bearings to make sure there is no extra play, or extra wear.
The engine involved is a DLE 50. Bearings have been replaced twice for no obvious reasons other than the fuel used. If I get a chance to talk to the owner of the engine, I'll get the detail for you.
qc