putting a 90hp on my pontoon > need blade help.

[rcl700]

I have a 20' aluminum pontoon that I have been working on over the winter. I have a 90HP TLDI tohatsu that Im also rebuilding the lower unit on over the winter. I plan on mating the two soon and dont know what prop to use.

the boat has no stickers on it to tell the weight but it does not seem heavy but sins it can not plain out I would think the prop would need to be a heavy setup.

Below is the prop chart from the tohatsu website it only lists 3 blade
I boats sells a 4 blade

I think Ill need a 13p based on this scale. Should I look at the 4 blade? This is a fish/ fun boat to be used in my local lakes. (I will be getting a aluminum prop) If I go with a four blade what would be a pitch?

M70C / M90 (2-Stroke)
MD70 / NSD90
(TLDI)
Dia., Pitch, blade
Light
12.75 21 3
13.2 21 3
13 19 3
13.2 19 3
13.25 17 3
13.25 17 3
Dia., Pitch, blade
Moderate
13.25 16 3
13.75 15 3
13.5 15 3
Dia., Pitch, blade
Heavy
14 13 3
13.75 13 3
14 11 3

 

[Bondo]

Re: putting a 90hp on my pontoon > need blade help.

Ayuh,... Is there a prop on the motor Now,..??

If so,... Marry the 2,+ Try it... Then you'll have a baseline to go from...

 

[rcl700]

Re: putting a 90hp on my pontoon > need blade help.

The prop has heavy damage. I'm rebuiding the lower unit because the prop shaft was bent. It was a 13p. But I have never had a motor on this boat yet so I don't have a base line only the tohatsu chart.

 

[Jeep Man]

Re: putting a 90hp on my pontoon > need blade help.

I don't know if my info would transfer to your Tohatsu, because of a gear ratio difference. I have a Merc Bigfoot with a 14x11 3 blade. I've tried a 9 pitch and it over revs. Ensure your motor is a long shaft. This is a must.

 

[cc350]

Re: putting a 90hp on my pontoon > need blade help.

I run a 15x13p on my 22ft pontoon with a 90hp Johnson