Jack plate problems

[coloblt]

Well, I have a 2018 z185 with g2 150 HO. I ran 52 mph at 5700 rpm without a jack plate. My dealer just installed a 4 1/2 inch slide master. I set it at 3 1/2 inches, my first trip to the lake it ran 47 mph at 5700 rpm water pressure 18-20. I then lowered it to 4 inches and I saw 49 mph with 5700 rpm. This is not what I was expecting, what should I do, keep going down? (22 raker HO at 5000 feet elevation).

[jc2bg]

That’s a tough one, at least for me. Not much elevation around here. The change other than setback is that a jack plate weighs something and can lower the stern, particularly on a shorter hull. Were the conditions and load identical in each test run? I’d guess you need to go higher, not lower, but am confused as you are by test results so far. What does your dealer say?

[coloblt]

That’s a tough one, at least for me. Not much elevation around here. The change other than setback is that a jack plate weighs something and can lower the stern, particularly on a shorter hull. Were the conditions and load identical in each test run? I’d guess you need to go higher, not lower, but am confused as you are by test results so far. What does your dealer say?

I failed to mention another change is that i also put an ultrex on replacing an edge. My dealer doesn't open until Tuesday morning... I realise I would go up for better preformance but, I was getting 4-5 mph more without a jack plate at 5 inches prop to pad...

[jc2bg]

I failed to mention another change is that i also put an ultrex on replacing an edge. My dealer doesn't open until Tuesday morning... I realise I would go up for better preformance but, I was getting 4-5 mph more without a jack plate at 5 inches prop to pad...

That trolling motor change could be significant. The Ultrex is quite a bit heavier, which on the bow of the boat can impact speed, especially on a boat that doesn’t lift so well. At the speeds you are running, it seems (seems means I am not sure of this) that your rig doesn’t generate a lot of bow lift, at least at that elevation. A prop change might increase bow lift and get your speed back to where it was, even some custom work on your present prop, or perhaps changing motor height will help. I don’t know what the Edge weighed, but I’m sure the Ultrex is more. Maybe also reduce tackle and other weight from forward areas of the boat?

[cconn]

My '18 Z185 ran 54 mph with no jack plate (Yamaha 150 SHO). Installed 6" Z-Lock plate and it currently runs 55 mph with 5" pad to prop. Have not played with adjusting the plate yet. Boat is currently in shop having an Ultrex installed, so I will post any speed changes when I get the boat back on the water.

[cconn]

I can now verify that removing my Maxxum and installing an Ultrex had no affect on top speed.

[MSranger]

CCon if your speeds decreased with addition to jack plate, why I stall one? Am I missing something? Just curious

[cconn]

CCon if your speeds decreased with addition to jack plate, why I stall one? Am I missing something? Just curious

My speed did not decrease when I added mine. Gained about 1 mph. The OP, Coloblt, lost speed when he installed his.

[slyz118c]

Sounds like you need to go up with the plate and try going up a pitch on the prop, to get you in the mid 50s

[mmusky]

Did you check your prop to pad? Did you try going up? Mine runs at 1 1/4 on the gauge but that is 3 1/2 below pad
http://www.bbcboards.net/showthread.php?t=157208

[coloblt]

After many trips to the lake and many adjustments, my boat likes the motor deeper, I'm like 5 inches prop to pad, and have maybe gained one mph. I have ran it all the way up and all the way down in 1/4 inch increment's. My guess is that it has something to do with the altitude here 5000 feet. The preformance is not really a heartbreaker for me, as my main reason was to mount a power pole and structure scan transducer.

[Tromanoski]

CCon if your speeds decreased with addition to jack plate, why I stall one? Am I missing something? Just curious

I never gained any speed when I installed one on my Z118 with a F150 Yamaha. I still get up to 55mph. It did drop to 55 from 58 when I added the two power poles before adding the jackplate. Ranger rigging department told me that they consider the main benefit for the addition of a hydraulic jack plate is to safely raise the engine while idling out of shallow water or a stump field. Others might have a different opinion but thats what Ranger told me before I added one. That's what I use it for too. When running wide open I have it on its lowest setting and let the trim do its thing for increasing speed. Heck if I was worried about speed I would have not bought a Z118 with a F150 on it nor would I probably would have bought a Ranger in the first place.

[psubob]

So I have the Z185 with the G2 150 and the 4 inch plate which was installed by Ranger when I ordered the boat. Mine is running now in hot weather at 56 -57 mph with two people, half tank of gas and a full load of gear. The PTP is right around 3 inches and its the stock Raker prop that comes with the boat, which I've read on here does not carry a load really well. This is trimmed out about 3/4 of the way. I have not played around with the prop height at all yet, this was the height it was set at by Ranger. The only reason I got the jackplate was to possibly install poles down the road and and I have my transducer mounted on the plate. I really like how quickly this motor gets from zero to 50.