Need some help with my outboard jet, Mounting height, Spray

Backroads
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Joined: 03 Jun 2014, 22:57
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Need some help with my outboard jet, Mounting height, Spray

Post by Backroads »

Ok guys, I'm in need of a little help and advice. I'll try to make this as simple and short as I can.

Just put this yamaha 40/28 jet on the back of my tracker 1648 grizzly. I had an older transom riser which wasnt enough, the leading edge of my foot was about 1/4 + below the bottom of my boat. While it ran good, it had a ton of backspray and just felt like it was dragging the rear end.

So I had a new riser made up to my specs, made to raise the motor up to be a little higher. Turned out the leading edge of my foot is just above the bottom of the boat now (as checked with a level straight edge) 1/4" maybe a tad more. I'm STILL getting crazy splash back, and still feels like I'm just dragging butt through the water.

I understand a splash plate will control splash, got that. I just feel like theres more to it to eliminate the problem before covering it up. My previous Mercury 25 4 stroke jet, never had this problem, apparently I nailed it first guess at install.

Now I went from a tiller with the 25, to a forward mounted console on the yamaha. Heres a picture of where the current setting is

Image

That is with the motor tucked all the way down as well.

Heres a short video I took this morning showing how much its spraying.



I got a trip planned for the weekend, was hoping to get this somewhat figured out by then! Hope you guys can help!!THanks!

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dhoganjr
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Joined: 10 Oct 2013, 04:35
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Location: Arcadia, MO

Need some help with my outboard jet, Mounting height, Spray

Post by dhoganjr »

From the picture I'm assuming it's a mod_v. Looks like it needs to go up another 1/4 inch or more. Aim for the straight edge to hit about the front pin for the grates. Also assuming you don't have power trim, raise it a hole or 2, happy medium between holeshot and top end. All the way tucked under=more of the shoe in the water=more drag and spray.

Looks like the way it sits now water is coming over the corners on the lip hitting the pump and back spraying the transom.
Dan
2003 1860 Alweld Flat Bottom
2014 Mercury 250 Pro XS Jet
2003 RiverCraft trailer
Retired from Riverlife-2002 Mercury 115 Fourstroke Jet

Backroads
Posts: 9
Joined: 03 Jun 2014, 22:57
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Need some help with my outboard jet, Mounting height, Spray

Post by Backroads »

dhoganjr » 02 Jul 2014, 15:36 wrote:From the picture I'm assuming it's a mod_v. Looks like it needs to go up another 1/4 inch or more. Aim for the straight edge to hit about the front pin for the grates. Also assuming you don't have power trim, raise it a hole or 2, happy medium between holeshot and top end. All the way tucked under=more of the shoe in the water=more drag and spray.

Looks like the way it sits now water is coming over the corners on the lip hitting the pump and back spraying the transom.
Thanks, it is a mod V style setup on the trackers. Not a traditional square front flat bottom. I do not have power trim. I was thinking to raise it up, I just thought it was getting a bit high, but then again I'm still new to this so whatever makes it work is the correct way! I'm more concerned with holeshot than speed, but I would HOPE this setup should hit 23 MAYBE 25mph. which is plenty for what I fish.

And you said about all the way tucked, should I not have it tucked in as much? I was just doing forum browsing and seen most recommendations to be all the way tucked.

Thanks for the help.

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dhoganjr
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Location: Arcadia, MO

Need some help with my outboard jet, Mounting height, Spray

Post by dhoganjr »

Most setups will work 1 or 2 holes out. That is an easy adjustment you can do on the water to see what it likes the best. Tucked all the way under forces the bow to plow the water robbing speed, too far out and it will porpoise or bounce and probably cause cavitation. That is what I meant by happy medium between the two.
Dan
2003 1860 Alweld Flat Bottom
2014 Mercury 250 Pro XS Jet
2003 RiverCraft trailer
Retired from Riverlife-2002 Mercury 115 Fourstroke Jet

Backroads
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Joined: 03 Jun 2014, 22:57
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Need some help with my outboard jet, Mounting height, Spray

Post by Backroads »

Sounds good I will give that a try as well, Hoping to raise it up tonight and head out early before work tomorrow and test it again. I will update with how that goes if I make it out!

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Jeeper
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Joined: 20 Apr 2013, 10:15
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Location: Lafayette, In

Need some help with my outboard jet, Mounting height, Spray

Post by Jeeper »

Second that imo from your video and pic it does look like it needs to be raised a slot or two hopefully that will help plus thats the simplest fix good luck
2001 SeaArk mv1860
2001 Bear Trailer
1999 Mercury 90/65 Jet

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LarryMc
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Location: SouthWest Virginia

Need some help with my outboard jet, Mounting height, Spray

Post by LarryMc »

Judging from the photo, it looks to me like it's tucked too far in. Jets don't always need to be tucked all the way in. It depends on the transom angle. Try trimming it out before raising it up any more on the transom. Outboard Jets recommend that the leading edge of the foot be flush with the bottom of the boat and the trailing edge about two inches lower. If you raise your motor up much more, you're likely to start having cavitation problems in rough water and on turns.

Link to Outboard Jet FAQ's below. Check # 13
https://outboardjets.com/faqs/
Last edited by LarryMc on 11 Jul 2014, 20:55, edited 1 time in total.
2011 Lowe Roughneck 1655CC - 2008 Mercury 2 Stroke 90/65 (Converted from prop 90)

Backroads
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Joined: 03 Jun 2014, 22:57
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Need some help with my outboard jet, Mounting height, Spray

Post by Backroads »

Well guys, couldnt get on the forum all weekend to report back. First I moved it up a set of holes and ran it, right away it was slipping on takeoff, once running it was WAY better, much quicker and more what I was expecting out of the motor with virtually no spray. Then I jumped back on and saw Larry's post about it being tucked in. So I dropped it back down and moved it out a hole at a time, well at 2 holes tilted out, I picked up my speed and lost a lot of the spray. It was running 25mph with my and another guy and our normal fishing load. Ran all over the susquehanna the past 2 days and had a blast. I think next I am going to make up a small splash shield as it does spray some, but not anything coming into the boat like before. Thanks for all your input and help. Heres a short video of running. Nothing crazy

.

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dhoganjr
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Location: Arcadia, MO

Need some help with my outboard jet, Mounting height, Spray

Post by dhoganjr »

Glad to hear you are getting it dialed in. Did you try trimming it out a couple holes before you lowered it back down. If you want to mess with it you can still get a little more out of it. With the spray it is still a bit low, maybe not a full hole, probably about a 1/4 inch. Still need the splash plate either way.
Dan
2003 1860 Alweld Flat Bottom
2014 Mercury 250 Pro XS Jet
2003 RiverCraft trailer
Retired from Riverlife-2002 Mercury 115 Fourstroke Jet

Backroads
Posts: 9
Joined: 03 Jun 2014, 22:57
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Need some help with my outboard jet, Mounting height, Spray

Post by Backroads »

I did move it out a hole when I had it raised up and it still slipped on me. I think I need to bring it up 1/4" and that will definately get me closer to the sweet spot. Only problem is the holes are spaced at about 3/4" so I guess my only option is to slot the top mounting holes? Would that be ill advised? I was thinking if I did that, I have some 1/4" aluminum plate I could rest the motor on so it wouldn't slide down after being mounted (since the bottom holes are slotted as well) Not really sure how else to go about that.

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dhoganjr
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Need some help with my outboard jet, Mounting height, Spray

Post by dhoganjr »

That is what we did originally with the 115, the dealer had it mounted too low. Funny thing when the 250 was installed it had so much torque that it kept twisting a little sideways after running it. I took the bolts out 1 at a time and filled the hole with quicksteel, let it dry and redrilled the hole. It stays solid in place now.

The way you mentioned will work fine, should hold it in place without any problems. Height set-up and impeller dressed and shimmed are the most critical areas with a jet. You try to get them to run as efficient as possible to make up for their inefficiency.
Dan
2003 1860 Alweld Flat Bottom
2014 Mercury 250 Pro XS Jet
2003 RiverCraft trailer
Retired from Riverlife-2002 Mercury 115 Fourstroke Jet

smackdaddy53
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Joined: 11 Oct 2012, 21:06
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Location: Victoria, Texas

Need some help with my outboard jet, Mounting height, Sp

Post by smackdaddy53 »

Backroads wrote:I did move it out a hole when I had it raised up and it still slipped on me. I think I need to bring it up 1/4" and that will definately get me closer to the sweet spot. Only problem is the holes are spaced at about 3/4" so I guess my only option is to slot the top mounting holes? Would that be ill advised? I was thinking if I did that, I have some 1/4" aluminum plate I could rest the motor on so it wouldn't slide down after being mounted (since the bottom holes are slotted as well) Not really sure how else to go about that.
You can always slot the top holes like you say and then drill another set of holes in between the top and bottom holes once you get it set and run it and know it is where it needs to be. Six bolts couldn't hurt right?
~Mac~

Bunten17
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Joined: 24 May 2021, 21:48
Location: Iowa

Need some help with my outboard jet, Mounting height, Spray

Post by Bunten17 »

I’m having the same problem with my Alweld 18/56 flat bottom! I have a 115 Mercury!
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