1985 force 125 2:1 lower unit

[Shifflett115]

I have a 1985 force 125 , i just got a 1985 force 85 parts motor with a 2:1 lower unit , i run a 4 blade 13 1/2 15 pitch prop , my top rpm is about 4300 , how much difference in rpms will i see going to the 2:1 lower unit , any info will be appriciated , thank you

 

[SkiDad]

about 600-700 rpm change - I have the same year as you. i love the new found torque - i can pull multiple skiers now like they are not there.

PS - what 4 blade are you running - did you have to modify to make it fit ?

 

[Shifflett115]

It is a turning point propeller , i bought it on iboats, it is for an 89 125 dual exaust unit ,the only thing i had to do is shave the anoid behind the prop alittle, i am looking for more tourque as we wakeboard and tube alot behind our boat , thanks for the info , i have a 1985 bayliner cuddy

 

[SkiDad]

turning point is very aggressive - i have one in 15p too but in 3 blade - it really runs like a 17p. But saying all of that - getting you to 5000 rpm will help alot. If you want more RPM i would look at the Michigan 13 1/8 x 15p - 072055

 

[Shifflett115]

what are your wot rpms with the turning point 15pitch and with the 17 pitch ?

 

[SkiDad]

with my normal load I'm about 5000-5100 with both the TP and a 17p stainless i had. My aluminum will run about 5600. I have a 15p stainless too that runs about 5200 ish. My boat is probably a little lighter than yours but I usually have 4-5 people on board.

 

[Shifflett115]

Thanks for the info , ill keep you posted on my rpms,

 

[Shifflett115]

Wow what a difference ,jumped out of the hole real hard with the 15p 4 blade on it ,now my wot rpms are 5100 ,didnt gain anything on top speed but im loving the extra torque !!!!!