'73 Johnson 115HP Powerhead into a '81 Johnson Base??

[mfarish]

Besides the obvious difference in the shift rod lever at the powerhead, can anyone tell me if this swap is legitimate?? Will the reed valve/intake casting from the 1981 fit on the 1973 model?? They look VERY similar........I have a blown '81 115HP engine with a good bottom end and a good '73 115HP top end with a bad lower unit....thanks

 

[fast_c_class]

Re: '73 Johnson 115HP Powerhead into a '81 Johnson Base??

i think 73 was an oddball year and is different in may aspects than any other year, including the powerhead bolt pattern. someone what to verify this

 

[Dhadley]

Re: '73 Johnson 115HP Powerhead into a '81 Johnson Base??

You can make a V4 crossflow with the late model bolt pattern (any 1977 140 and all V4's 78 and newer) retro fit (change the 4 threaded holes) back to 73. Using an older bolt pattern block on a late model mid section will result in a water leak where the water comes up and into the block.<br /><br />Get a base gasket for your 81 and compare it to the base of the 73 block and you'll see the difference in the water entry area.