1968 35 hp mercury

[andrzej]

friend of my has the motor
runs great
120 psi on both cyl
but the lower leg is cracked
whats the options ?
it must be the same motor to replace the leg ?
it must be mercury ?
which leg will fit that motor ?

 

[Chinewalker]

Similar year Merc 35 and 50 horse models will interchange the lower ends. Yours appears to be a short shaft, so that will be critical if you don't plan on doing a driveshaft swap (fairly major surgery). They changed the lower units in the early 1970s from an 11-spline propsshaft to more splines (12 or 13, can't recall off the top of my head) and a larger diameter prop shaft. Other changes, too, with larger mounting studs, shift shaft arrangement changed, etc. Pretty sure a '66 to '70 will work. Check an online parts listing to confirm.

 

[andrzej]

thank u
what i understand is 50 hp mercury lower leg will fit the 35 hp if both are short shaft
what years of the 50 hp i have to look for ?
1966 - 1970 ?
he was told until 1972

 

[Chinewalker]

Could be '72 - it was along in that era of the early 1970s that they made the changes. But yes, any 50 lower unit of the same era as your 35 will work. They were the same lower ends year for year.

 

[racerone]

Carbon steel driveshafts.-----Not that many around in very good condition.----The 3 cylinder 65 HP may also fit.----The 3 cylinder has a different gear ratio.

 

[Chinewalker]

65 triple came out after they changed the shafts and studs, so it won't fit without modifications. Also, short shaft 65s are rare, if they made them at all.