Nissan NS5B upgrade question

edimusrex

Recruit
Joined
Aug 18, 2015
Messages
2
I am curious if any one has any suggestions on how to get a little more horsepower out of an Nissan NS5B outboard. Even 1-2 extra horsepower would suffice, I am just not in the position to drop $1000 on something bigger. I noticed that the larger models , 6,7,8 use the same carburetor and am wondering if popping a larger carb in would work. I am assuming on these models the jets are slightly larger depending on the horsepower. They are all single piston 2 stroke engines so does any one know if that will work and if not does any one have any suggestions to push this thing a little harder?

Thanks
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Welcome to Iboats,

You should have purchased a larger engine, but will not discuss about that. Can't upgrade a 5 HP, it's already on its top range, you could with a 4 HP as both are same CC, just with different carbs. That small portable is being used to push which boat type, how many passengers, want to plane the given model boat, better the fast displacement performance ? Need more info.

For that to happen, need to install an induction tach, go for a wot spin you alone while lightly loaded on flat calm no wind water cond and check achieved max wot rpm, compare them to engine's min-max safe wot range, then can go from there maximizing prop to better whatever you hope to accomplish..

Happy Boating
 
Last edited:

edimusrex

Recruit
Joined
Aug 18, 2015
Messages
2
Thanks for the reply. I'll leave it as is. It's actually pretty decent for what I use it for ( 2 people on a 14' Jon boat on a reservoir ). I'll consider purchasing a larger motor in the future, was more curious as to weather or not it was possible.
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Although can't upgrade to a higher HP, cam maximize prop to push better that combo with 2 up.

Happy Boating
 
Joined
Aug 9, 2015
Messages
7
I agree with Sea Rider. My NS8B is a two piston motor so it's might not work, even if it does bolt on. Your best option is to figure out what propeller works best with your setup. Just changing to a more efficient prop will make a noticeable difference. Good luck and God bless.
 

PoorBaylinerGuy

Seaman Apprentice
Joined
Jul 22, 2012
Messages
49
I don't know how much HP you can have on that resorvior. But I used to fish one that limited to 10hp. Had a 5 HP Nissan motor, then a 15 mercury. And to be straight honest I caught bigger fish while using the 5hp! And I missed it when I got rid of it. Don't underestimate 5hp!
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Larger engine, more noisy it gets, fishy gets acared faster and running they go...LOL. A 4-5 HP OB will take you there and also back from there.

Happy Boating
 
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