1989 Yamaha ProV 150. What gear ratio on lower unit?

[JoePA]

My buddy purchased a boat that has a 1989 Yamaha ProV 150 on the back but no lower unit. It's a 20" shaft engine and wants to purchase an SEI lower but not sure if it's a 1.86:1 or a 2.00:1

Anyone got an idea? It's on an old Switzer craft and it weighs next to nothig so I would assume the 1.86:1 will work fine but don't want any issues proping it.


Thanks
Joe

[21XDC]

Both will work, but Yamaha puts 2.0's in all of the 150's and you will need a 23-25P prop depending on the boat and how fast it is. The 1.86 is for the 2.6L 175 and 200 hp motors although they will all interchange.

[JoePA]

Mike,
Thanks! I'll let him know what he needs. I was thinking 23 to 24 tempest or whatever Yamaha prop would do the trick.

Thanks!

Joe