Hi
I have dis-assembled an OS 91 FS II pump engine for cleaning. How to know when the bearings need to be changed? When I spin the bearing it does so noiselessly but after the bearing has been soaked in thinner for about 2 hours, it makes lot of sound and does not spin smoothly. But after a few hours and some lubrication, it came back to normal. It this OK?

What kind of oil should be used to re-assemble the engine? I can not use the after-run oil as the engine has a pump. Can I use the SAE 15W/40 car engine oil? We do not get Klotz or Marvel oil in India.

Thanks

Vikas