2016 Z18 175 Pro XS New to me Boat.

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Cub48

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Hi Guys I just bought the Z18 a couple weeks ago. And have added a few things to the boat 6" jack plate, 1 eight foot power pole, added electronic ect. I have a few questions. I have owned boats most of my life so this is not a first boat. I have read about these questions on here and other places but have not found the answers that i am looking for. I am not wanting to run a 100 mph LOL. Just good all around performance. 1. Installed jack plate to install power pole. My pad was 3 1/4" the boat was porpoising when you slowed the boat down to like 25 mph, got it up to 62 mph was fine. Load was 1/4 fuel just me 100 lb tackle
 
Do I raise or lower the engine to stop porpoising at low speed. 2. My prop is a 24 pitch fury it does ok but the holes are open on a 175 ProXS 2 stroke how should this prop be setup 123 plugs or none. Need full fishing seat for front besides Nitro Dealer Most i found have lite gray mine are charcoal and black. May have to buy two to get match Cub48
 
Trim motor down or increase speed to stop porpoising. I am not familiar with jackplate performance, but if you have a hydraulic jack I would guess it should go down a bit.

Is your motor a 2 stroke or 4 stroke? If it's a 4 stroke my understanding is the prop vents should plugged.
 
Hi Guys I just bought the Z18 a couple weeks ago. And have added a few things to the boat 6" jack plate, 1 eight foot power pole, added electronic ect. I have a few questions. I have owned boats most of my life so this is not a first boat. I have read about these questions on here and other places but have not found the answers that i am looking for. I am not wanting to run a 100 mph LOL. Just good all around performance. 1. Installed jack plate to install power pole. My pad was 3 1/4" the boat was porpoising when you slowed the boat down to like 25 mph, got it up to 62 mph was fine. Load was 1/4 fuel just me 100 lb tackle
Mine was doing the same, I started trimming down when slowing down and took care of the problem.
 
I had my P-P at 3 1/4" and when i would slow down it would start to porpoise. Yep i know to trim down but i had to trim way down to stop it. It is a 2 stroke 175 PRO XS my question is do I move motor up or down to help the porpoise. Thanks for the reply Cub48
 
First thing about hyd. jack plates in shallow water lets say 2' jack plate all the way up and motor trimmed all the way in. For regular running and hole shot you are going to have to find the sweet spot for that, all the way down or half ect. And when running slow you will need the jack plate all the way down to pull the nose down and trimmed all the way in. For top speed run the jack plate up about a 1/4" at a time and trim the motor to have no more then a rooster tail above the cowling. Also keep an eye on the water pressure gauge. That fury prop runs best with no plugs .
 
I had my P-P at 3 1/4" and when i would slow down it would start to porpoise. Yep i know to trim down but i had to trim way down to stop it. It is a 2 stroke 175 PRO XS my question is do I move motor up or down to help the porpoise. Thanks for the reply Cub48
I have the same Motor on my Z18. Your trim controls the porpoising. You answered your own question. The jackplate is used primarily to allow you to get on plane and off plane in shallower water. And you can get greater fuel efficiency when raising the motor in relatively stable water. You lower it for better control in heavy seas. See the links below. Yamaha Outboards.


 
Hi Guys I just bought the Z18 a couple weeks ago. And have added a few things to the boat 6" jack plate, 1 eight foot power pole, added electronic ect. I have a few questions. I have owned boats most of my life so this is not a first boat. I have read about these questions on here and other places but have not found the answers that i am looking for. I am not wanting to run a 100 mph LOL. Just good all around performance. 1. Installed jack plate to install power pole. My pad was 3 1/4" the boat was porpoising when you slowed the boat down to like 25 mph, got it up to 62 mph was fine. Load was 1/4 fuel just me 100 lb tackle
I have this 2019 Z20 in the picture, it has a 225 ProXS when I first received delivery to my new boat I got a box full of stuff with it. In that stuff was a bag with different plugs in it. After calling Mercury Marine I found out that those holes you are referring to in the prop help with your hole shot. I run mine without any plugs, the holes are all open. With the trim all the way down and my Atlas Hydraulic jack plate raised 1/2" my boat explodes out of the hole shot, it nearly comes out of the hole on plane. "If it's not broke don't fix it" This boat according to my dealer is the fastest Nitro he has ever test drove. He says he had it at 78 mph and it has more. I have 2 10' Talon's on my boat it's 20'2" with a 112 thrust MinnKota Ultrex on the front. The porpoising issue is something you need to tinker with. Best results for myself are to gradually slow down rather than a faster decline. I also have the ProTrim levers for the trim and jack plate on the steering column, this makes it very easy to trim down as I decelerate, I have a hotfoot so no need to have the hands on the shifting lever. Hope this helps you..
 
Thanks everyone for your replies. I know getting use to a different boat is something that will take a while, learning all the different thing that make the boat feel like it is supposed to. Like i had a 150 Yamaha last boat and getting use to a Mercury is a lot different. I am just trying to get everything setup like i want it then won't have to mess with it. Going to put a hole shot plate on i have a buddy that can make me one. I adjusted hot foot cable yesterday, put boat buckles on, going to adj motor up 1/4" and will be done. Cub48
 
I have the exact same boat. My mid shaft to pad is 3 1/2 inches. Pad to top of cavitation plate is 4 inches. I have an 8 inch jackplate. I porpoise as well, but trimming and quicker speed smoothes it out. Nitros at this length 18.8 are know to porpoise somewhat. Many friends have had the shorter boat and it happens to some degree. Change prop to a 4 blade maybe. I run 65-67 WOT
 
HTW thanks I have mine set at 3 1/2" now and it is a lot better. I have almost got everything like i want . I have had the boat about 3 weeks now taking me a while to get use to everything my Stratos had a Yamaha 150 and was a lot quieter. I am having a issue loading as it seems that the winch and roller are too high. I have tried different positions backing in .But still high. I ran 62 mph but not wot. I would like to try a 4 blade prop as i had one on another boat I had, I liked it. Cub48
 
Sounds like you are putting the trailer in too deep. If the trailer is too deep, the nose of the boat won't rise as it slides up the bunks. Leave at least 6-8 inches of wheel and fender out of the water. It is better to back the trailer too shallow than backing it in too deep.

I had a Stratos 189V years ago. The shape of the bow is quite different on the Nitros
 
Check your prop. I would guess you are running a 24P Fury which came with the boat, but have read threads mercury put the wrong prop on boat. If you are getting mids 60s, the prop is fine. I took my prop in to get cupped and it made a difference getting out of hle and top end (cheaper than a new prop. Going to a 23P will raise RPMs about 150, but top end will make no difference. Also, you can raise your jack plate 1/4 inch at a time to find the sweet spot.
 
Tim C i fixed the loading problem i cut the winch support off and welded it back i have loaded my boat about five times and have not had any problems drove all the way to the ring with my fenders just out of the water. Like i have always done on my other boats. Before I did the repair i had trailer to where boat would not push itself all the way up and the roller was hitting the rub rail and i would have too put strap on and make it go over the roller. As of right now everything is going good just taking me a while to get used to this boat. I think I have about everything adjusted like i like want it had to adjust the trim sensor, trying to get used to the Lowrance on the front so i won't have to buy another humminbird to go there. Got another seat for the front. Bought a vessel view mobile for engine temps and other items. Put the ratchet buckles on trailer. Just all the small things that i like then when i get it like i like it i will be done!! Cub48
 
I own the 2017, Z18 with the 150 four. I ordered my boat with the Atlas haudraulic jack plate. My experience with the 150 four is that the jackplate has little to do with speed or porpoising. I have never had any issue with porpoising. you have to trim the motor back down as you slow down. I"ve never owned a big boat where that wasn't true.. It's just an automatic reaction with me. When slowing i begin to trim the engine down coming off plane, otherwise it will begin to hop. My top speed (GPS) has always been 57-59MPH with the Z18. I don't see a significant change with the height of the jack. We fish a lot of shallow water so I use my jack a lot. The value of the jack is operation in shallow water keeping the lower unit off stumps and out of the mud. If not for this consideration I doubt that I would ever invest in one. Just my two cents guys....
 
Hi Guys Since i put my p to p at 3 1/2" it has been better if i slow down to like 26 mph i have to trim all the way down to get it to stop porpoising but if i start trim as i slow down it it is a lot better. I am just having to learn new boat. I had Stratos boats the last two boats and they were not as hard to control the porpoise as the Nitro. Cub48
 
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