Lowe 20' pontoon prop

racoutlaw

Recruit
Joined
Mar 29, 2012
Messages
2
I have a 1990 120hp evinrude on it now(yes little big for boat).
It had a 17pitch prop on it(stainless) motor would do 4800rpm and gps showed 24mph
Changed to a 15pitch aluminum motor 5000rpm now gps shows 27mph.
Motor is a ve120txesb is this good or would I need to goto a lower pitch?
With this motor the pontoon boat is heavy in the rear end sits little low till moving at good speed.
Thanks for the info.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Lowe 20' pontoon prop

Your performance is certainly acceptable.Slip is about 23% perhaps a little high but pontoons do produce high slip numbers.
I think a 13" 4 blade prop may improve things a little. May lower slip. I wouldn't necessarily expect a big increase in speed with a pontoon but some and control around the dock should improve.Also if you have had any venting(cavitation) that should improve.
If the motor is over the rating You may want to check the condition of the motor pod also there could be legal issues if anyone is hurt.
 

racoutlaw

Recruit
Joined
Mar 29, 2012
Messages
2
Re: Lowe 20' pontoon prop

Thanks for the info
Just want to make sure that my rpm is in the right rang for being at wot
The motor is over sized rated for a 75hp
Transome was wood but had a boxed in one made for it out of 1/4 inch. Aluminum
Not much money to play with just something I put together on a budget
Got boat with trailer for $500 and motor I got for another $500. Put about $300 in motor to get it running
Guess I still good for what i have invested
So do you think my rpm is good as is or do I need to get them higher?
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Lowe 20' pontoon prop

Sure can't beat the investment. Your rpm range is 4500 to 5500 So your right in the middle.
Should work fine.
 
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