1953- 1954 evinrude lightwin 3HP 3012

[redgolds]

Does anyone know what the compression should be on this motor? Also how thick are the piston rings for this motor part number 203152 or 378412 which is the new part number so I a told. I am trying to rebuild this motor that I purchased but I found out that someone replaced 1 of the pistons that is a different part number with a different piston ring size. It looks like the original ring thickness should be 3/32". Does this sound right?

 

[southkogs]

Moved ya' into the outboard section ... you were in the OMC stern drives. You'll get better answers faster over here

Welcome aboard.

 

[F_R]

378412 is the correct part number. I believe they are 3/32". That probably is a 4hp piston with the skinnier rings.

 

[lindy46]

65-70psi minimum

 

[redgolds]

Thank you so much for all of you that got back to me. This is my first motor overhaul and it has been a challenge. I just joined i boats and I feel like you're all like family so far. Glad that I joined.

 

[Crosbyman]

http://www.outboard-boat-motor-repa...Johnson 3 HP 1952-1967 Carburetor Tune-UP.htm

http://www.leeroysramblings.com/johnson_magneto.htm

http://www.leeroysramblings.com/OB carburetor_repairs.html