2016 Merc 115 4 stroke

[allen656]

My son has a Tracker 190tx with the Merc 115 4 stroke,came from the dealer with a 3 blade aluminium 12.5 x 23,he is interested in a Merc Spitfire 4 blade aluminium.

I don't see the 12.5 x 23 listed,can he move up to a larger diameter prop and keep the same pitch?

Right now runs 5800 rpms at 42 mph


thanks in advance

[21XDC]

When going to a larger diameter, Sometimes you need to reduce pitch because the slip is normally less.

[model70man]

What kind of tachometer does he have? I foumd out that my Faria factory installed analog tach is off by almost 300 rpm. I would recommend a 21p or 19p Spitfire prop. I have a 21p stainless Spitfire and it runs my boat 53 mph.

[allen656]

ok,thanks....14" dia you think?

[PECo]

What kind of tachometer does he have? I foumd out that my Faria factory installed analog tach is off by almost 300 rpm. I would recommend a 21p or 19p Spitfire prop. I have a 21p stainless Spitfire and it runs my boat 53 mph.

model70man

At what rpm do you get 53 mph?