1970 Johnson 115 Gear Ratio and Prop Size

P

Phishin

Cadet
Joined
Aug 2, 2010
Messages
25
I have a 1970 Johnson 115 on a 1970 18' closed bow fiberglass Starcraft.

I'd like to get rid of my aluminum prop and get a stainles.

The OEM tach on my dash says that I'm at 3000 RPM's at WOT. My GPS says I'm traveling 28-29mph. The prop currently on the boat is a Michigan Wheel #01004, which is a 13 x 19 3-blade.

All the proper calculators want the gear ratio, and all I could find was that most were 2:1, except a few including my motor.

Can anyone tell me what the correct gear ratio is for my motor? I assume I want to be at 5k RPM's at WOT, correct? So what prop would you recommend? I can plug the info in the calculator, just didn't know if anyone knew by real field experience.

Thanks you in advance.
 
P

Phishin

Cadet
Joined
Aug 2, 2010
Messages
25
Re: 1970 Johnson 115 Gear Ratio and Prop Size

TTT.

Is there a reason no one is replying? JW.

Maybe I'm missing some kind of board etiquitte or asking the wrong question. Sorry to be hounding the experts. Just trying to get my boat ready for a musky trip to Lake St. Claire.

Thanks.
 
You must log in or register to reply here.
Top