Question on rods on 90 merc

[BOAT DOCTOR]

I'm rebuilding mercury 90 3 cyc lack of oil is the reason it burnt up. My question is on all 3 of the rod at the top by the piston pins the rods are a little grayish look wonder if i should replace the rods

 

[CharlieB]

Re: Question on rods on 90 merc

Greyish isn't all that bad, if ANY blue showing a LOT of heat and MUST BE replaced.

Rod problems usually begin on the big end as the bearing speed on the crank will melt bearings when run without oil.

The small end has very little bearing speed in comparison. You may be seeing a bit of heat that radiated from a heated piston, but for a fishing motor you should be fine.