'71 Merc 800 "center main" bearing question

[Faztbullet]

Re: '71 Merc 800 "center main" bearing question

Only tools I have to measure internal diameter are telescopic bore gauges. Is that good enough to determine wear or is something more precise required?

A quick way to check is to run a rigid hone thru the cylinder..the worn areas will show up as shadows in cylinder where the stones did not touch.

 

[Moody Blue]

Re: '71 Merc 800 "center main" bearing question

Will look into renting/borrowing a hone. Might even buy one if they are reasonably priced. I can see how that would show the high points but it won't tell me "how much" out of round it might be.

I took photos of the center main bearing race for you inspection. Wondering if they are still useable or should be replaced. The marks that are visible on the one half of the race are barely detectable using the tip of a ball point pen. Very small pitting, if thats the right word. In an ideal world I would replace them BUT what I'm wondering is do they HAVE to be replaced?