Looking for compatibality on powerheads for a lower unit off of a 1978 140h. joh

[koikrazy]

Anyone know what powerheads/years will fit on this lower unit. I have all but the block and the pistons off the 140. I just want to get something to work 4 it. It would be a big help to know what different powerplants and years this lower will handle the #'s off the motor are 140TL78c and j4990451 its a johnson sea horse Mag Flash cd 140 horse 1978 outboard

 

[Dhadley]

Re: Looking for compatibality on powerheads for a lower unit off of a 1978 140h.

Re: Looking for compatibality on powerheads for a lower unit off of a 1978 140h.

All V4 crossflow blocks from 1978 on will match the bolt pattern. A 1977 140 will too. Blocks from the 1977 115 and 85 will match as long as they came from a 25" motor. <br /><br />There was a main bearing change in 1979. If you use a block from 1979 on you will have to use a crank from 1979 on. If you use a crank with an O ring in it for the driveshaft, you will need the bottom seal plate for that crank.<br /><br />The rods are all the same from 1974. I would use the latest model heads you can find although any will work as long as they are kept in sets. <br /><br />Good luck!