1974 18' starcraft holiday what size prop

[nowakezone]

on this old starcraft we use to have a mid 70's v4 115 crossflow with a 17" prop and rev 5500 +/-150 rpm now we are putting on a 89 140 and just wondering where to start with a prop we bill be using an aluminum prop.

this is the same kind of boat i found online we did take some weight out of the boat no more back to back seats just 2 seats and we put a new floor

 

[steelespike]

Re: 1974 18' starcraft holiday what size prop

I would start with the prop on the motor no prop use the 17.
I think the gear ratio is different on the 140.Do a base line test and get the prop size,max rpm and speed to us.We can figure out a prop.The 17 could be close.Depending on the ratio.If you end up needing a prop check out the Turning Point Hustler.Close to stainless at aluminum prices.

 

[nowakezone]

Re: 1974 18' starcraft holiday what size prop

I'm pretty sure the 140 has a 2:1 gear ratio i was thinking of a 19 right off the hop cause the old 115 was rated at the engine and the 140 is rated at the prop the guy who i bought the motor had a 20" raker i have that prop but it has a fair bir of damage on it and he told me this motor was on a bayliner a fairly heavy boat!