# Thread: Running the Little Su w/13.5' Zodiac-fuel consumption?

1. ## Running the Little Su w/13.5' Zodiac-fuel consumption?

Just curious as to what kind of gph I can estimate running my (actually my dad's-he's giving it to me) 13.5' Zodiac up the Little Su with two guys, fishing & overnight camping gear with a 15hp 2 stroke long shaft? Will I have issues running a long shaft up the river from the landing? I've run the 15hp (late '80s Johnson) a lot (on a flatbottom jon boat) in the Big Lake area but never calculated gph as fuel wasn't an issue. I assume I won't need nearly as much gas coming down!

On another note, any idea what kind of gph a 20 hp 4 stroke will get compared to the 15 hp 2 stroke? I'd like to get a 20+/- hp 4 stroke eventually so I don't have to borrow my dad's 15hp Johnson, just don't know if I can do it this year.

Any help?

Tim

2. ## Variables

Way too many variables in this equation. Hull shape, inflation, weight of load, gradient of the river, volume of water, .... But a 4 stroke uses less fuel compared to an equal H.P.

3. I can't tell you the GPH on your 2 stroke but what ever it is you will get about twice as much when you switch to a 4 stroke.
Our lodge boats are 17' Lund Alaskans with 30 hp 4 strokes.
80 mile round trip at full throttle uses about 9 gallons of fuel @ 21 MPH.
When we had 2 strokes the same trip used about 18 gallons.
So when you use your dad's 15 hp see the fuel consumption and then realize that you can go the same distance with a 4 stroke using 1/2 the fuel.

4. Originally Posted by DRIFTER_016
So when you use your dad's 15 hp see the fuel consumption and then realize that you can go the same distance with a 4 stroke using 1/2 the fuel.
I think that's what I'll end up doing. The Little Su trip is purely to figure out gph. I want to go upriver for a few hours at full throttle and gauge fuel consumption. We'll probably do a June &/or August trip, should be lots of water.

Do you guys know if I'll be ok with a long shaft? 20" I think. Is there a bracket I can use to raise the motor for shallow water?

Thanks,

Tim

5. with normal to high water you can run a long shaft up river. Just be good at reading the water.

I used to run the little su in my 12' lund with a 8hp evenrude, was perfect combo. I haven't been thier in years due to the "yuppy launch/camp ground", that place used to be magical. Now, just a tourist trap and Aholes with way to large of boats/motors.

6. You will certainly "rub" bottom with the prop and if the water is low forget it. you may try the big su to the deshka then you got some fish and you can run the river. Still will probably "rub" but not nearly as much or bad.

7. Originally Posted by AKDSLDOG
with normal to high water you can run a long shaft up river. Just be good at reading the water.

I used to run the little su in my 12' lund with a 8hp evenrude, was perfect combo. I haven't been thier in years due to the "yuppy launch/camp ground", that place used to be magical. Now, just a tourist trap and Aholes with way to large of boats/motors.
I was there a few years ago with my dad's 14' & 15 hp and was nearly wiped out by some guy (more than one) coming around the corner with these powerboats with 150 hp engines. I felt tiny in the 14'.

Tim

8. Originally Posted by akdube
You will certainly "rub" bottom with the prop and if the water is low forget it. you may try the big su to the deshka then you got some fish and you can run the river. Still will probably "rub" but not nearly as much or bad.
That's not a bad idea. I've been to the Deshka too. That would be a good trip.

Tim

9. hard to get too far upstream with a prop maybe 2 or 3 miles if I remember right

10. ## Go downriver

You would be better off running down river from the launch at the Lil Su. Upriver is too shallow for a prop unless the water is very high and you are pretty good at reading water.
After a few bends going downriver the water gets deeper and is slower but murky. I've seen lots of Zod's and small prop boats running downriver during silver season.
BK

11. With the setup you are describing, you should be runnning a 15" short shaft for optimal performance. Be sure to have an extra prop and cotter pin on hand when running that 20"er in the rivers, because you're bound to jack the first one up on the bottom. Take it easy or both may get trashed.

12. ## Like Larsenvega said,

seems a short shaft motor would be better on a small zodiac? Also, don't forget the tools to change that prop/pin/nut. I tried a longshaft 18 hp Tohatsu once on a friends 12 or 13 foot zodiac and was too scary; the boat was all over the place and was too "squirrely". It needed a short shaft motor. We only did it once it was pretty bad.
Jim

13. ## minimal exp

I have extremely minimal experience on the little sue (or any othe river for that matter) - but I have been upstream of the launch 2 times......ooooh...

I wouldn't recommend going up that river full throttle in any boat except a canoe with paddles.....a head on collision with another boat could be the worst you could do - pissing off several shore fisherman would be your best case scenario. If you want to check your gph - use the big sue for running.

14. I live right by the Little Su and boat it very frequently and I started with a zodi on that river. I started off with a 25 horse that was ok downstream. Up stream, not so much. Then, I changed to a 20 hp jet pump and that made it so I could go up and down stream with ease. My zodi (I still have it) drags on extremely rare occasions. While I do think your outboard is questionable for shallow rivers, your boat is just fine. As with all boats in shallow water, it is important to have enough power to be completely on step. Otherwise, like others have pointed out, your trip is going to be a drag.....

15. Why not put in on the "other" end and "float" it with your zodiac?

Camp about half way down and take out at the other end.

Gas wouldn't be a big deal then.

16. Maybe running down from the launch and then back up would give me the consumption results I'm looking for. This Little Su trip is to do a little fishing and figure out fuel consumption....

I guess since it isn't a secret spot I can reveal my REAL intentions. My ambition is to take this set-up and run it down the McClaren (sic) and then back up, that's why I like to figure out my gph. I don't want to run down the McClaren and not have an idea of how much fuel to bring. I may have issues with the 20" long shaft, so that trip may have to wait until I get a short shaft 4 stroke.

Is there anyway to "lift" the motor a little out of the water to run shallower water, or will that make the boat ride & plane differently?

Thanks for the ideas; didn't realize the Little Su was so shallow above the landing.

Tim

17. I've seen some ghetto-rigged transom extenders made out of anything from wood to aluminum plates. They bolt them down to the transom and look a bit scarry. It probably works, but I'd hate to see what might happen if they hit a rock while under a decent current or speed. That extension would probably snap off and send your motor into the drink. I swear that those guys must have hired MacGyver to come over to their house to hook it up...

18. Originally Posted by tccak71
Maybe running down from the launch and then back up would give me the consumption results I'm looking for. This Little Su trip is to do a little fishing and figure out fuel consumption....

I guess since it isn't a secret spot I can reveal my REAL intentions. My ambition is to take this set-up and run it down the McClaren (sic) and then back up, that's why I like to figure out my gph. I don't want to run down the McClaren and not have an idea of how much fuel to bring. I may have issues with the 20" long shaft, so that trip may have to wait until I get a short shaft 4 stroke.

Is there anyway to "lift" the motor a little out of the water to run shallower water, or will that make the boat ride & plane differently?

Thanks for the ideas; didn't realize the Little Su was so shallow above the landing.

Tim
Once you get your gph roughed out, which I think at best you'll get an idea but not a true figure you can bank on due to varying conditions etc...., then you need to figure out a % over just the fuel needed for the trip; to take as a contingency or reserve.

19. Originally Posted by ak_powder_monkey
hard to get too far upstream with a prop maybe 2 or 3 miles if I remember right
It is somewhat shallow 2-4 miles upstream from the launch, but once you pass 6 miles from the launch it is plenty deep for the next ten river miles. I run a 5 hp on my canoe and just tilt the engine forward in shallow water to avoid the rocks.

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