Yamaha 70 lower unit and compression

[CU2NITE]

Can any one tell me if a 1990 50hp lower unit will fit on a 1984 70hp? Also I checked the compression and the they read 125 122 105. What do you guys think of those numbers? The 105 has me concerned.

 

[rowbards]

Re: Yamaha 70 lower unit and compression

not sure about the fit but I don't think so...have you done a leak-by test? If so what were the %'s

 

[Jammu]

Re: Yamaha 70 lower unit and compression

What is the type of your 50 hp. Is it the "normal" 50 (698 cm¤)or is it the 50 (849 cm¤)?? If it's the bigger one, then the lower unit will fit the 70hp engine.<br />There is a smaller prop axle in the 50 (849 cm¤) than on the 70hp. The type is G-axle on the normal 50 and the "Big 50", and the 70's axle is K-type. <br />The "Big 50" is called Pro50 or 50G here in Finland.