Top end speed issue

[1pabassman]

I have a 2011 200hp optimax proxs, it's on a 1998 20ft astro,having problems getting any kinda speed out of it,here is what I've done,set my height to 3 inch below pad, tried a lazer 21 pitch prop and got 50mph at 4700 rpm wot, then I tried a lazer 23p same result 50mph at 5100 rpm wot,then a 25 trophy ,was a disaster,46 mph at 4100 rpm wot, last I put a 24p tempest and got 49 at 4200 rpm wot, all had great hole shot but could not get top end,water pressure was around 18psi wot 4lb at idle, I'm at wits end I'm afraid there is an issue with the motor itself,I purchased last nov from a dealer last nov an this is the first time out due to heart surgery,can i please get some ideas or recomendations., fyi I have a vessel view and node fault codes come up,and no alarms

[EuropeanAM]

If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info (serial number) when posting. Thanks!

Has this engine ever performed properly for YOU, on this BOAT? A little history here may help.

[1pabassman]

Sorry it is a 2011 200hp mercury optimax proxs, serial# 1B863737. As far as it running right,well I purchased it from a dealer in va,back in late november,it is used an only had 85hr total use on it,when I got back home in pa I tested it and had an issue with a sensor an oil pump leaking,so after thanksgiving they came an got the boat an fixed it an till I got it back it was snowy so I got one run down the lake and it ran fine,fast foward to this spring I have not had it on the lake till this past week because of heart surgery an other mounting health issues so I really dont have an answer except the motor runs good,starts right up,jumps on plane and runs good ,the issues I'm seeing is no speed I had a 99,175 efi prior to this 200 and I run full tournament load with the 23 p prop an I run 63mph all day so I would assume I should be getting atleast that with this optimax,and just cant get it,now I did correct my battery,issue,i didnt realize i had a deep cycle battery instead of a cranking battery,not sure if it makes a difference because it starts fine but i did swap out for a 1000 mca starting battery today but have not tried it,so I'm hoping i dont have a motor issue but i figured that would show on my vessel view?

[lpugh]

Check the throttle for range of operation, inspect the belt make sure the tensioner it in good shape ( minimum of 70 in. lbs before it reaches the stop using torque wrench to remove the load on the belt) not the retaining bolt

[1pabassman]

What belt?

[castforcash]

What belt?

The belt for the compressor and alternator, right on top of the motor.

[1pabassman]

I dont understand what that would have to do with speed ??

[JOE54]

just making sure likely causes of low power dont exist with your engine because if its only turnning a 21 pitch prop 4700 something deff wrong with mtr or boat , start with basics comp, spark, fuel delivery, linkages , sensor , operation or enlist services of a known good MERC tech

[1pabassman]

but wouldnt those things show up on my vessel view if there was a problem

[JOE54]

some might

[1pabassman]

ok let me ask,if i was using the wrong battery for cranking,would that effect the motor,

[JOE54]

yes sir sure can , good place to start correct batt

[1pabassman]

ok i was using a deep cycle series 29 battery and went and got a 24 xms starting battery with 1000 mca to put in

[SilverFox579]

1000MCA (800CCA) meets engine only minimums, you really need something with 950+ COLD cranking amps and 200+ mins RC.

BATTERIES THAT MEET THE REQUIREMENTS

[1pabassman]

why? if youre talking about a battery bigger to allow for electrical, i have everything hooked to a series 29 deep cycle,and my 3 units have a seperate battery,and my book calls for a 1000 mca with atleast 105 rc this battery has 135

[EuropeanAM]

Your book states the MINIMUM capacity (not "it calls for"). And that is for the engine only, without any accessories (and without any other batteries tied in by any form or fashion).

Additionally, by the time you add up the weight of your 29 series Deep Cycle and the latest added battery, you're probably much better off with ONE cranking battery that significantly exceeds the minimum specifications (ie: BARE minimum of 950 CCA, or COLD Cranking Amps).

[1pabassman]

well i already have the extra 29,so what im doing is mounting it in the port compartment in the rear and adding all my electonic stuff off that battery, this way the weight is distributed even and i can do away with my battery that was mounted in the starboard rod box for my electronics i can run everything off the one battery with no interference.will putting this cranking bat only in make any difference with the motor issues or should i say low top speed ?

[EuropeanAM]

Battery or voltage problems can affect the engine under any condition from "key in the cranking position" to Wide-Open-Throttle (as well as anything in between).

Your engine has a myriad of electronic devices that must all be able to function at correct voltage in order for the engine to perform properly.

[1pabassman]

Thank you sir,as always I will let you know how I make out after Wednesday I will be taking it to the lake to test again

[Judson1]

1000MCA (800CCA) meets engine only minimums, you really need something with 950+ COLD cranking amps and 200+ mins RC.

BATTERIES THAT MEET THE REQUIREMENTS

I ran into this the other week. Very few offerings with that kind of power. Interstate doesn’t even offer a battery that strong. I bought the strongest they had which satisfies Mercury requirements. I know accessories drain them but it was the best I could do locally.