150 hp Mercury Optimax turning 5400 rpms at 54 mph. Suggestions?

[zprice7]

I would like to get opinions on how to get a little better performance out of my boat.

I have a 2011 Nitro Z7 with 150 opti. Running 5400 rpms at 54 mph with 21 pitch Tempest Plus.

Prop to pad 3.5” with 6 inch jack plate
Water pressure 20 psi as I just changed the water pump. Before changing the pump it was at 13 psi so didn’t want to move motor up anymore.

New fuel filter and changed spark plugs.

I have made some good progress on this boat as it was running 5000-5200 rpms at 50-52 mph with a 24 tempest plus before. I am just wanting some input or suggestions on how to get it running 5700 rpms and 58-60 mph like it should be running. It is not plowing water and has good bow lift. Hole shot is VERY good at about 2 seconds.

Any thoughts or suggestions?

[RAErwin]

My 2011 150 Opti Pro xs on Z7 is turning 5400 at 61 mph 3.25 below pad with the tempest plus 24. Are all cylinders firing?

[zprice7]

My 2011 150 Opti Pro xs on Z7 is turning 5400 at 61 mph 3.25 below pad with the tempest plus 24. Are all cylinders firing?

They all appear to be firing. The motor runs great which is why I don’t feel as if there is something major wrong with it. I just think there might be some deeper issue as to why it’s not running what it should be.

[RAErwin]

The 21P prop seems a bit short for that setup. BPS sold those boats back then with the 24P, and you'll never get 5700 with that prop and still have good water pressure. Most guys I know swapped the 24 Tempest Plus for a 23 and rigged it at 3.5" bp and were pleased.

[Fishysam]

Something seems off like not getting full throttle. Take cowl off and have someone push to full throttle and verify the full travel is happening

[RAErwin]

I've heard that a coil not firing will affect performance while the engine still sounds great. I never had that issue directly but I've repeatedly read about surprised owners finding this problem.

[ammdrew]

Mine was best with a 22... with that said Raise the prop a half inch and see how it does, Then try another half inch... just watch your water pressure.

[zprice7]

The 21P prop seems a bit short for that setup. BPS sold those boats back then with the 24P, and you'll never get 5700 with that prop and still have good water pressure. Most guys I know swapped the 24 Tempest Plus for a 23 and rigged it at 3.5" bp and were pleased.

I would 100% disagree with the 21p prop and water pressure statement. My water pressure with the 21p prop at 3.5” ptp is 20 psi. Plenty of water pressure there. And running 5400 rpms. Are you trying to say that I should get 5700 rpms with a 23 or 24p prop and good water pressure?

I used to have a 24p on it and only ran 5000 rpms at 52 mph at 3.5” ptp with good water pressure.
I have tried a 23p prop on it at 3.5” ptp and still only ran 5200 rpms at 54 mph and also good water pressure.

That is the exact reason as to why I feel as if there is something a little deeper going on with the motor but I do not know what it is.

[zprice7]

Something seems off like not getting full throttle. Take cowl off and have someone push to full throttle and verify the full travel is happening

I have verified that it is, in fact, getting full throttle.

[RAErwin]

[No, what I meant to convey is that my 24 can only turn a max of 5400 before I raise it too high to have adequate water pressure. I've never been able to come close to 5700 with my 24P. Most of the guys that I know with Z7's are running the 23P and get closer to the target rpm's. Based on that experience, the 21 seems like it would rev much higher. QUOTE=zprice7;11244337]I would 100% disagree with the 21p prop and water pressure statement. My water pressure with the 21p prop at 3.5” ptp is 20 psi. Plenty of water pressure there. And running 5400 rpms. Are you trying to say that I should get 5700 rpms with a 23 or 24p prop and good water pressure?

I used to have a 24p on it and only ran 5000 rpms at 52 mph at 3.5” ptp with good water pressure.
I have tried a 23p prop on it at 3.5” ptp and still only ran 5200 rpms at 54 mph and also good water pressure.

That is the exact reason as to why I feel as if there is something a little deeper going on with the motor but I do not know what it is.[/QUOTE]

[zprice7]

RAErwin, ok that makes sense now. I will also try to test the coil packs and see if one of them isn’t firing like it should be. What is the best way to test that?

[RAErwin]

You would have to ask someone else for that answer. I've only read numerous times how "the engine sounds great", and everything else was checked out (as you seem to have thoroughly done); then I read the surprise in their follow-up comments about how a bad coil ended up being the problem.

[Bdog]

My 2013 Z7 with a 150 has a 24P Temp with no JP and it run 62 easy with me and my wife and with 30-35 gallons of gas. 62 (GPS) It ran this way this past Friday with and air temp of 90-95 deg. F

Now with that said Nitro did replace my hull this year, but it did run like this when it was new.