1988 Fisher 18' GT 1988 Evinrude 90

[JasonAych]

1988 Fisher 18' GT 1988 Evinrude 90

My boat currently has a steel prop. The only numbers I can make out are 133170, which as far as I can see is only part of the evinrude number.

The boats seems to rev too high, just over 6k, at WOT. I want to go to a higher # pitch or larger diameter to bring the RPMs down. The problem is there are no other numbers on the prop so I don't know where I am starting from.

I also plan on going to alluminum since the water I will frequenst tends to be shallower and full of rocks.

I went through the "Prop Wizard" which recommended a 13.25x19.

Any thoughts, does 13.25x19 seem reasonable? Maybe sombody has a similar setup and can recommend something?

 

[JasonAych]

Re: 1988 Fisher 18' GT 1988 Evinrude 90

Anybody? Did I not include enough information??

 

[Dhadley]

Re: 1988 Fisher 18' GT 1988 Evinrude 90

I would think a 19 would be in the ballpark. I'd suggest taking the prop to a prop shop and have them measure the prop. They'll give us an idea of what it is and we'll go from there.

I'd be hard to recommend a 19 and then find out that's what you have that turns the extra r's. At that point a 21 would be something to consider. Also if your ss prop is a 19 and you go to a 21 aluminum you may - depending on what style aluminum prop - still end up with still too many rpm.

 

[JasonAych]

Re: 1988 Fisher 18' GT 1988 Evinrude 90

Since 133170 is the only number I found on the current prop, is it possible it is a 13.3x17?

 

[Dhadley]

Re: 1988 Fisher 18' GT 1988 Evinrude 90

Might be but once you have a prop shop measure it we'll know for sure.

 

[Dhadley]

Re: 1988 Fisher 18' GT 1988 Evinrude 90

Have you removed the nut and spacer to look for numbers on the hub?

 

[JasonAych]

Re: 1988 Fisher 18' GT 1988 Evinrude 90

Prop is off. I looked it over good.

Not sure I have a "Prop Shop" anywhere near me.

 

[Dhadley]

Re: 1988 Fisher 18' GT 1988 Evinrude 90

Do you know anyone with a 17 or 19 (or even a 21) that you could borrow for a quick test?

If you have a dealer nearby ask them about prop shops. Most dealers have at least one prop shop that sends someone around at least once a week.