crankcase checkvalve function

[JT!]

1987 merc 70hp

i have a couple checkvalves in my crankcase, and they are missing the plastic stop valves. prolly melted away, is my guess.

what is their function? to siphon fuel thru the bearings and cycle it to the other bearings? does it matter that the little nylon balls inside the checkvalves are missing?

 

[Chris1956]

Re: crankcase checkvalve function

The nylon balls make the valve work as a pump. You should replace them.

BTW why did the engine get hot enought to melt 'em? Was there other damage as well?

 

[JT!]

Re: crankcase checkvalve function

this is the engine i bought with the cracked crankcase, cracks caused by the #1 connecting rod coming thru sides. bearing smeared, having a cam-like effect on the big end, forcing it into the sides.

so far i've ordered a replacement bearing, and am looking at repairing the case with JB weld.

i think the heat was created by a bad oil pump. not sure. apparently old owner was trying to pull another boat free from a sandbar (freshwater)