Decompression lever / keeping engine lubricated?

[er9]

Quick question.

If for example i am working on wiring, cooling system or whatever and cant start the engine for long periods of time, could i use the decompression lever to manually rotate the engine once a week to keep oil in the places it should be?

Also...if the engine hasnt been started in a long time would it be useful to spin the engine slowly by hand (decompressed) to get oil onto the piston walls before starting normally?

[Lepke]

I don't think you can spin the engine fast enough by hand or starter to get oil on the cylinder walls. With the engine running, oil escaping the main and rod bearings is flung about the crankcase with some landing on the cylinder walls. Then distributed by the rings.

Hand cranking isn't going to produce much oil pressure and may remove some of the oil on the cylinder walls.

[Compass790]

I can only say it works in our engine using the starter motor AFAIK but our YSM8 is a horizontal cylinder & the crankshaft balance weights splash in the sump so I'm almost certain it would fling some oil to splash on cylinder walls. Wether it works on a vertical cylinder I don't know Also the oil pressure goes up to 40 psi so it must be pumping thru the oil galleries. I always spin it up on decompression till the oil pressure gets up to 40psi before starting coz it gives me a warm fuzzy feeling. Wether it makes any difference to engine life I don't know but it can't hurt. Your engine, your choice.