Jet height and angle

Creekchub
Posts: 16
Joined: 04 Aug 2020, 20:40
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Jet height and angle

Post by Creekchub »

Good afternoon
First time poster and new to me jet Jon boat.

I bought a 17’ express boat with a Honda 50/35 jet. Ideally I would have liked a larger motor but couldn’t afford it.

My question is I have the motor lined up with the leading edge of the foot so it’s level with the bottom of the boat but the back end looks too low. Is that possible?

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JL8Jeff
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Joined: 26 Oct 2013, 14:56
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Location: Ewing, NJ

Jet height and angle

Post by JL8Jeff »

The back will be down farther to allow the water to flow into the intake. I have a jet tunnel and run with the front a little below the top of the tunnel and with the motor tucked in all the way (to eliminate porpoising) which gets the back of the foot even lower. When I went 1 hole higher on mounting the motor, it gave me too much spray back over the transom and slowed it down a little.
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2001 Lowe Roughneck 1652 VT with Merc 60/45 jet 2 stroke

Creekchub
Posts: 16
Joined: 04 Aug 2020, 20:40
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Jet height and angle

Post by Creekchub »

Here is two pics of my set up. The motor is trimmed down to the lowest pin setting. I have only ran it once and it was one pin setting higher
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JL8Jeff
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Location: Ewing, NJ

Jet height and angle

Post by JL8Jeff »

That looks about right to me. If you start to trim it out/up, you'll start getting a lot of spray back. The back of the foot has to sit lower than the front to help it take in water. You might be able to mount the engine 1 hole higher but my guess is that you will get more spray back and it might start to cavitate. But trial and error is needed with every setup, it took me at least 4 tries to get it set up the way I like it. But I was happy to find a jet tunnel hull which helps get the motor higher. The previous owner had a prop longshaft outboard on it when I bought the boat.
2001 Lowe Roughneck 1652 VT with Merc 60/45 jet 2 stroke

Creekchub
Posts: 16
Joined: 04 Aug 2020, 20:40
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Jet height and angle

Post by Creekchub »

Thanks jlb for the feedback. The boat ran ok on the higher setting but it didn’t feel optimal. It ran about 22 mph. Beats paddling any day of the week but I think I can tweak it a little. May replace the impeller and liner too

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Lil' Blue Rude
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Joined: 13 Jan 2011, 00:58
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Location: SE, Mo

Jet height and angle

Post by Lil' Blue Rude »

You can raise your motor some more. Depends on what shape your boat bottom is and your impeller you can raise it so the bottom is about even with the pin holding your grates in the front of the shoe. Seems high but the medium size pumps can usually run that high without cavitating.
16' 42" Blazer SS with a custom short shaft 60/40 Evinrude

1gr8bldr
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Joined: 18 May 2020, 16:54
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Jet height and angle

Post by 1gr8bldr »

In my experience, non tunnel, the leading edge of the jet foot is higher or level with the boat hull. The rear of the foot or heel is about 2+inches lower.