jrs_diesel
Chief Petty Officer
- Joined
- Mar 3, 2010
- Messages
- 552
I am rebuilding a 72 Johnson 6 HP. Are the wrist pins re-usable?
My service manual does not give the specifications for the diameter of the wrist pins. I took a lot of measurements of the original pins with a micrometer, and based on my measurements, both pins are both perfectly round. Both pins measured at .422 inches.
One pin (lower cylinder) looks great, and fits the connecting rod well, and the conn rod bearing looks great too. No slop or wiggle at all.
The upper cylinder pin looks good too, no slop between it and the conn rod. There is a very slight scuff that I saw on one end, likely where it fit the tight end of the old piston. I can just barely feel it with my finger, but my fingernail does not catch when I run my finger over it that way. It looks nice and smooth where the conn rod and pin actually meet.
I feel comfortable re-using them, unless there is something wrong that I don't see.
My service manual does not give the specifications for the diameter of the wrist pins. I took a lot of measurements of the original pins with a micrometer, and based on my measurements, both pins are both perfectly round. Both pins measured at .422 inches.
One pin (lower cylinder) looks great, and fits the connecting rod well, and the conn rod bearing looks great too. No slop or wiggle at all.
The upper cylinder pin looks good too, no slop between it and the conn rod. There is a very slight scuff that I saw on one end, likely where it fit the tight end of the old piston. I can just barely feel it with my finger, but my fingernail does not catch when I run my finger over it that way. It looks nice and smooth where the conn rod and pin actually meet.
I feel comfortable re-using them, unless there is something wrong that I don't see.
