115/90 Jet on 18' john?

[icbronze]

I have a neighbor at camp who put a 115/90 jet on an 18' john so he could be the fastest on the river. His maiden voyage did not go very well. Is there anyway this setup cold ever work?

 

[Ranchero50]

Given his reason for doing it, Nope.

 

[Lil' Blue Rude]

Ok need a little more info. What didn't go so well with his maiden voyage? How wide is the boat and what motor did he put on the back? 2 stroke or 4

 

[icbronze]

The boat is lowe 1860, a lot of water was splashing over the back, it got up but was porpoising extremely bad. Will a boat that size handle 425 pounds of outboard. I believe it is a 4. Would flotation pods help? thanks

 

[Lil' Blue Rude]

does he have the transom built up or does he just have a jack plate on it? If it's bouncing it's got to much weight in the back, trimmed to far up, or the boats got a lot of rocker on the bottom.
Sorry to say he's not gonna go fast with a big heavy 4 stroke. I don't think the boats to small but the 4 strokes are just heavy.

 

[Seth]

An 1860 built for a jet motor will run the biggest outboard you can slap on it. Lots of guys running 250 Mercuries on 1856 Alwelds around here. My boat is an 1852 with a 115/80 Etec. It won't break any speed records by any means (runs 35-37 mph).

 

[user 6672]

I have an 1856 Alweld JC with a 115/80 jet on the back, as Seth said.. not the fastest ship in the fleet but she does what i need her too..

Make sure your buddy at camp balances his rig the best he can,batt's up front to counter the outboards weight is a good start..

 

[S&MFISH]

icbronze » 29 Jul 2013, 15:47[/url]"]The boat is lowe 1860, a lot of water was splashing over the back, it got up but was porpoising extremely bad. Will a boat that size handle 425 pounds of outboard. I believe it is a 4. Would flotation pods help? thanks

I had the same problem when I bought my 1756 Alumacraft w/ 115/80 Merc on it. Joe at Troutt and Sons hooked me up with the solution.


The tail alllows me to trim the engine up enough to stop the excessive splash,but controls the porpoising.

 

[Seth]

My Legend came with trim tabs on each of the back corners of the transom. I think those and the whale tail like S&M has on his Mercury pretty well accomplish the same thing but I could be wrong. The purpose from my understanding was to help the boat plane out a bit quicker.

 

[icbronze]

Thanks guys, he was not up last weekend. I will give him info next weekend and let him decide.

 

[Lobsterol]

I have an 1860 alweld with a 115/80. It runs 35 mph with 2 people, fishing gear, and a full cooler. It has factory welded trim tabs on each side. The boat does not cavitate unless you trim the motor to high, which is about over 25% up. Hope this helps.

 

[Seth]

Lobsterol » 09 Aug 2013, 16:52[/url]"]I have an 1860 alweld with a 115/80. It runs 35 mph with 2 people, fishing gear, and a full cooler. It has factory welded trim tabs on each side. The boat does not cavitate unless you trim the motor to high, which is about over 25% up. Hope this helps.

That's how fast my 1852 runs. Did you tweak your motor a lot to get those speeds? I would have thought at 115 on an 1860 would be in the low 30 range.

 

[Lobsterol]

Seth » 12 Aug 2013, 13:05[/url]"]

Lobsterol » 09 Aug 2013, 16:52[/url]"]I have an 1860 alweld with a 115/80. It runs 35 mph with 2 people, fishing gear, and a full cooler. It has factory welded trim tabs on each side. The boat does not cavitate unless you trim the motor to high, which is about over 25% up. Hope this helps.

That's how fast my 1852 runs. Did you tweak your motor a lot to get those speeds? I would have thought at 115 on an 1860 would be in the low 30 range.

It actually runs 34 mph. No carpet, No interior sides, perforated floor, I only fill the tank with the amount of fuel I'll need that day.

 

[semojetman]

I used to get 34 down river with mine until i added more and more gear. Now in down to 30 all rigged up.
But, i only got a 60/40 on an 1856