Nitro Z7 w/ 150 optimax

[flashman252]

Brand new to me boat (barely used 2008 z7 with 150 optimax with only 105 hours), came from dallas area and it is clean clean. Now it has a 23p tempest plus. I took it straight to the lake after picking it up (couldn't help myself) and it did not want to get on pad. Altitude of lakes where I am are 4000-7000 ft. Most lakes I fish are in the 4000 neighborhood. Was only pushing 2900-3000 rpm when launching and the few times it bumped 3300-3400 rpm it did get up on plane and ran great. When it was on pad, only getting 4800 rpm. So I am figuring I am way over propped and mercury website recommends a 19p. Is there anyone else running a similar setup and if so, which prop pitch are you running? Also, this boat does not have a JP and will be adding one but just not sure when. What Prop to pad measurement are you guys seeing is a good setup? The motor is mounted in the second to bottom hole (so two holes above the screw and one hole below the screw) and I have not honestly measured the prop to pad measurement yet. I really appreciate all the replies and thank you guys in advance.

[jb882]

Are you sure its firing on all 6? That vintage of Opti had some coil issues where they would randomly fail. I had to replace a few of mine over the years on my 2008 175 Pro XS. Its easy to check, take it to the lake, run it and then pull the plugs. If one is soaked with fuel its not firing. The strange thing is when the coil goes bad they start and idle perfect but when you try to get on plane it will feel like its breathing thru a straw and have zero performance once it gets on the pad.

As far as your setup goes you sound fine to me. 23p is the factory prop from Nitro and the motor position sounds correct for no jack plate on this boat if i remember correctly. The only variable may be the altitude, you man need to pitch down some for that but i would make sure the motor is solid first.

Once you get your plate on there its a little different. I have a 6" plate and I run mine at 2.75" below pad as does a friend of mine that also has 2008 Z7 his with a 150 opti on it and a 6" plate. Both run real well with that height, he runs a 23 Tempest and i run a 24.

[flashman252]

jb882 thanks for your reply. Ya altitude is a killer for all boats here. I've done a lot of asking around locally with similar setups (19ft boat and 150 hp) and almost everyone here is saying a 23p for this setup is way too much prop. Even talked with a guy in colorado running a similar setup and they said the biggest prop he could get away with was a 21p at altitude. Very good to know about the spark plug issue. I ordered a 19p and am going to try it out. If i have the same issue then it is obviously not the prop. I will most definitely look at the coils and plugs next time out. I did manage to get it on plane 3 times and when it finally jumped up, it ran great except the fact that I was only running 4800 rpm and nowhere near the 5750 rpm for WOT. We fish lakes from 4000-7000 ft altitude. 2.75" with a 6" plate. That is key information I was looking for. Thank you for this bit of information as well.

[Fishysam]

Just making sure, you have the throttle pinned down while trying to get up and the motor is all the way down?

then when it gets up and going by the time your going 4500rpm you have it trimmed all the way up?

[flashman252]

Yes I was definitely trimmed all the way down. Actually, I am glad you brought this up and maybe I can get a little insight and thoughts. When i couldn't get it on plane, I tried different trim angles when before pinned the throttle. What I found was that the motor would drop down to the rams. The few times it did get up on plane, i was then able to trim back up and the trim worked fine again. So trim worked when at idle, worked on the trailer, worked when on pad. Trim fell though when I mashed on the throttle trying to get on plane. I figured it needed to be all the way down when jumping up on plane but you get desperate when you get a new boat and it is struggling to get on pad. With that said, should the trim fall like that down to the rams when throttling down for launch? I was going to check hydraulic fluid in trim next day off, and I have gone outside the last three nights and looked at it to see if I can see anything leaking and can't but I have also read that there may be internal leaking with the seals in the main lift arm of the trim. Thoughts on this guys?

[jb882]

What do you mean when you say the rams? Are you talking about the two short arms that come out of the trim? The main arm or the big center one is not used in operation, that is the "tilt" function of the tilt and trim unit. If you are trimmed past the two short arms, yea it will bleed it down pretty quick if you apply throttle to it.

I made a video in case my text here is confusing.

[flashman252]

Jb882 i truly appreciate your video. In no way did I take it that you were trying to imply that I know nothing about boats. Been around boats most my life but this is my first bass boat and I am sorry if I come off with dumb questions most should know. No guidance here but bass fishing has got me by the balls the last couple years, its a truly terrible addiction boys. The boats I have been around though have not been 150's and definitely much smaller. So your explanation in the video is great and kudos to you sir for taking the time to make the video. What you explained in the video makes me believe now there is absolutely nothing wrong with my trim unit now. I was referring to the rams as the two short arms. Again, first time out, I was desperate to try different angles of the motor to try and get it on plane. Even with it all the way down it wouldn't quite jump up. Again, altitude is killer where I am at. Have a 19p prop on my doorstep, will hopefully be testing this weekend and if not saturday, then for sure next week. Thanks for all the help and replies. Think I am pretty ok as far as questions go. JP is the next task and will hopefully be ordering next week. Looking at hyrdodynamics. Like the ease of use and have read multiple issues with binding with JP with the top screw. Anyone got JP recommendations? This should open this thread right up. Planning on a 6" JP, can't justify a hydro jack plate at this time and maybe never will but I want the ability to change prop to pad measurements and dial in the sweet spot.

[jb882]

I would bet that 19p is going to get you going, if it doesnt then it may be time to have that motor gone over to make sure its 100% healthy.

As far as a plate goes. I have a 6" manual slidemaster on mine. I got it as a factory option when i got the boat in 2008 and i have been real happy with it for the 12 years i have had it. I dont think you really need a hydro plate at all, once you get it really dialed in there should be no need to adjust the height again. At least that is how it has worked for me, i got it dialed in and its been the same since for 12 years. One thing to note, set the boat up with the gear you intend to run in it. It makes a difference for sure.

[Fishysam]

Before smashing the throttle you need to have the motor as low as it will go.

after the boat gets going like 30 mph start bumping the trim up one second at a time wait a few seconds bump again and repeat.

trim- 2 rams. Must be trimmed all the way down. All the way.

tilt - large center piston only used at idle speeds and idle throttle or off

[flashman252]

Yes sir got it. Boats I've been around have 1 single arm, and never fell under load, hence the ridiculous questions guys so sorry about the confusion on my part. Think I have a pretty good grasp on this now, hoping the small pitch prop jumps it right up. Unfortunately i doubt I'll be able to get away this weekend to try it but definitely next weekend I'll have it out.

[mean_dean]

I can attest to altitude, when I moved from San Diego to Denver, my 61 mph Ranger 361V with a Yamaha Pro-V 150 because a 45 mph lead sled. Local dealer reworked the carbs and I played with props and best I could get was still only 54 mph, ended up with a 21p tempest+ as a 19p would hit the rev limiter.

[flashman252]

Im worried about the 19p being too small and hitting rev limiter. I know a couple boats around here now that run 21p's that are similar in setup but they are still a little low on the RPM's but a whole lot closer than where I am. There is a lake that is 7000 ft here and I think the 19p will be good for that lake. Worse case, I order a 21p for some of our lakes and keep the 19p for the higher elevated lakes. Other thought is I keep hearing about Mr. Croxton adding cups and reworking the prop to form more of a 20p. This might be worth a shot and able to use at all lakes? Anyone had any work like this done? And sorry if this thread is all over the place at this point. We went from setup, to trim/tilt explanations, to jackplates, to props now. If this is getting out of hand, I understand if we need to start a new thread.

[jb882]

Im worried about the 19p being too small and hitting rev limiter. I know a couple boats around here now that run 21p's that are similar in setup but they are still a little low on the RPM's but a whole lot closer than where I am. There is a lake that is 7000 ft here and I think the 19p will be good for that lake. Worse case, I order a 21p for some of our lakes and keep the 19p for the higher elevated lakes. Other thought is I keep hearing about Mr. Croxton adding cups and reworking the prop to form more of a 20p. This might be worth a shot and able to use at all lakes? Anyone had any work like this done? And sorry if this thread is all over the place at this point. We went from setup, to trim/tilt explanations, to jackplates, to props now. If this is getting out of hand, I understand if we need to start a new thread.

I have been running worked props on my boats for 20+ years now. Its kind of like buying a suit off the rack vs. a tailored suit, they both may look good but only one will fit you perfect. My Z7 is running a 24 tempest plus that was cupped and reworked by DAH Propeller, i have had them do work for me a few times over the years and they are top notch for sure.

I would not do any work to the prop until you have the boat dialed in with a factory prop as best as you can get it. From there a good prop shop will be able to work with you to dial the prop in better. They will need data on the setup and RPM, speed etc and what you are looking to change be it better holeshot or more top end etc. Its a process for sure but its not the first step to take, you have to get the boats basic setup lined out first.

One other thing to think about. If you are someone that has a tendency to smack up props than having one worked may not be the right choice to make, it would get real costly real quick. Consider where you boat as well, that alone can make a difference on whether you never hit anything or risk hitting stuff constantly. If you are new to bass boats you may want to get some experience under your belt before you dive in on prop work. I personally boat on bigger lakes that have a lot of shallow rock but are deeper where you would actually be running, if i fished shallow obstacle filled water i probably would not have a worked prop on my boat, it would not be worth it.

[flashman252]

jb thats great advice. Some years our lakes are plum full and the risk of hitting anything is nil. Years like this year, our lakes feel like puddles and good ol Texas keeps wanting their water rights so we keep emptying our lakes..... (gonna stir that pot a little). So the obstacles and chances of hitting stuff are definitely greater. I do not plan on getting a worked prop just yet, I definitely want to go try this 19p, then the next step would be to get a 6" JP and dial in the prop to pad. Run it for quite a few trips, get comfortable with it and then consider a worked prop depending on performance of this 19p. It might just send it straight to the rev limiter and I may need a 21p all together but I really do not think that will be the case with the elevation and the last poor performance the boat had with the 23p. Again, serious ass time in the boat is what is seriously needed. Took the time to install fishfinders the other day and ensure I have my navionics in the boat. It is a MUST right now with our lakes being low. Knowing where that channel is important to ensure not wrecking boats right now. Our lakes are real rocky and have deep bluffs. Not a ton of silt unless you get way up the river channels but thats more catfishing country and if I am venturing up there, I am pulling out the havoc with mudbuddy instead. Thats off limits to the bass boat.

[Tumbthing]

Flashman i have a 09 Z-7 that i have been fighting planning issue myself. i finally got it working better than i have in the past. i got a Chris bailey plate and put a mercury bravo 1 20P 4 blade on it and it worked for me i can get on plane no issues, 1/2 tank plus of fuel two people and gear and half my livewell filled. i am running 53 mph at 5700 rpm

[flashman252]

Tumbthing, what altitude are your lakes that you're on? I have a 19p that I will be testing this weekend. Also, I will be ordering a jackplate very soon. Good to know about the 4 blade and the 20p working for you. Also, if you don't mind me asking, what is your prop to pad measurement? I saw on the nitro performance thread at the very top of Nitro boats forum that a lot of z7's were set 2-3" range. Plan on putting a hydrodynamics 6" very soon. I keep reading how good these plates are.

[Tumbthing]

well i live in Florida so altitude is very low, my pad height if i measured right is about 3.5". i have a 6" manual jack plate. the Bravo 1 is an 15.25" prop. but if the boat likes it who am i to argue. unfortunately mercury has stop making the standard bravo 1 in 20P i think they start at 22P now. but i ordered a bravo 1 FS 21P and it should be fine with a little extra RPM.

[jb882]

well i live in Florida so altitude is very low, my pad height if i measured right is about 3.5". i have a 6" manual jack plate. the Bravo 1 is an 15.25" prop. but if the boat likes it who am i to argue. unfortunately mercury has stop making the standard bravo 1 in 20P i think they start at 22P now. but i ordered a bravo 1 FS 21P and it should be fine with a little extra RPM.

I bet your motor height is most of the issue. My buddy when he got his Z7 with a 150 it took forever to get on plane with the setup as delivered from the dealer. His was also ~3.5" below pad on a 6" plate with a 23 tempest plus. Raising the motor up to 2 3/4" and changing the PVS plugs to have a little less ventilation fixed it totally, i think he has 2 med and one large plug in there like i do. Its now every bit as quick as my boat is with the 175 to jump up on pad, under 3 seconds with my normal gear and half a talk of fuel where i normally run my boat. Add a full tank or a passenger and it does not slow down much. Where you put weight also matters a lot, i load all the heavy stuff up front which helps get offset the livewell water and fuel load.

[flashman252]

Tumbthing, I am running much higher elevation. The lowest lake I run is 3000 ft elevation and highest is 7000 ft. I checked my prop to pad and it is 3.5". I am starting to think the guy I bought the boat from never changed anything on the boat from the day he bought it. 23p prop, 3.5" prop to pad, 10 year old fishfinders that didn't work, etc. etc. Hell the motor only has 105 hours on it in 10+ years. The tires on the trailer were original as well, figured that out with 2 blowouts on the way home with it. With that said, I will be getting it out on Sunday, will update you all on how it performs with the 19p prop, and the jackplate will be ordered Monday morning. Meant to get to it today but got busy and forgot to make the phone call. PVS plugs are on order, so testing will be with wide open plugs. From what I understand, the more open the plugs, the better the hole shot because it is creating exhaust bubbles to allow the prop to spin quicker. The more bubbles create less clean water though so I do understand there is a balance act here and will take some experimentation to figure out.

[Tumbthing]

Good luck, hope it all works out, i will have my Bravo 1 21P FS Monday, i will do test runs next week sometime. as you fight the altitude i fight the heat and humidity. my boats definitely runs better in the fall and winter when it cools down a bit. summer time running tends to kill the performance of the engine, plus this 150 has over 300 hrs on it. i am going to run it til it dies and put a 200 on.