225 Optimax lacks power

[Ga_strat_273]

Hello I have a 2002 mercury opitmax 225 serial # 0t587111. Running a renegade 4 blade 13 1/2 x25 prop. I purchased the motor on a 2005 nitro 911 cdc hull about 2 months ago. The problem I'm having is the motor has no hole shot fires up and runs fine without hesitation. But when I take off it motor trimmed down correctly the motor turns 3000rpm and takes forever to plane out. And once on plane the motor is only turning right at 5000 rpms and is not is not running out but about 52mph.

My question is that what could be the possible issues? I've changed spark plugs, fuel filter, primer bulb, fuel lines any possible culprit think of just need some help on running down the issue so I get back to fishing.

Thanks in advance.

[EuropeanAM]

Has the engine ever performed properly for you, on this hull, or is this a new-to-you rig or engine?

Moving your thread to the correct (3L) forum for you.

[Ga_strat_273]

It's a new to me rig I've taken it out twice and both times I've had the issue.

[EuropeanAM]

Thanks for clarifying.

Two recommendations:

1. Check to make sure you are reaching the WOT position at the engine. If you have a hotfoot- there's a "Hotfoot Setup" post in the FAQ Section (near the bottom).

2. See if you can get your hands on a 24P (could try a 23P but 24 is likely good) Tempest Plus prop to try. Don't have any data on the suitability of that Renegade, but suspect strongly that it's not a good selection. Medium or Large PVS plugs should give you a general starting point.

(Note: If you don't have a Smartcraft Instrument, it would be wise to look into one as you really do need accurate RPM readings to achieve proper setup).

[Ga_strat_273]

Ok thanks. I will look into the hot foot setup and the prop pitch and brand. and the smartcraft instrument as well.

[Ga_strat_273]

One additional question could there be any other issues that may contribute to my problems electrical fuel delivery ect...?

[EuropeanAM]

Absolutely. Dozens and dozens of possibilities. Given your particular situation- I would recommend starting with Post #4 and depending on what you find for results, will be glad to assist further if necessary.

[Ga_strat_273]

I'm unable to find the hot foot setup post mentioned in post #4. Where can I find the FAQ section?

[EuropeanAM]

Look at the top of this Forum, there are several PINNED posts there.

[Ga_strat_273]

I found it thanks a lot

[lpugh]

As Don mentioned I think you will best suited with a 24 tempest with one hole empty and two with the large hole plugs. May work with one if you lift just a little at nose over. Should rev about 3500 to 3800 before the the bow breaks over for best hole shot. This prop should get you close to 5700 this time of year maybe a little more at lower elevations ( under 1000ft) I never did like the renegade props on anything
Also check the prop to pad height and start at about 3.75 and raise it 1/4 at a time and check top speed, water pressure and how it handles. After finding the best height for your rig you can revaluate pitch change or prop work needed
If you are willing to invest 300 for prop mods on top of the purchase price of a prop, I think you would find a 24 Fury would work very well for you
Mark Croxten would be the man to do the prop work, he is a board sponsor in the prop forum. Michael the moderator for the prop forum is a wealth of knowledge regarding props and setup
Were you trimmed up high when doing 50MPH at 5000 ? should have been
If numbers are correct and tach is accurate you have 26% slip (highly suspect)
Check tach accuracy by verifying with smartcraft or a digital tach
If tach is correct, you may have motor problems as well as propping issues
Try to borrow a 24 tempest to try and be sure to check the tach as a starting place

[Ga_strat_273]

As Don mentioned I think you will best suited with a 24 tempest with one hole empty and two with the large hole plugs. May work with one if you lift just a little at nose over. Should rev about 3500 to 3800 before the the bow breaks over for best hole shot. This prop should get you close to 5700 this time of year maybe a little more at lower elevations ( under 1000ft) I never did like the renegade props on anything
Also check the prop to pad height and start at about 3.75 and raise it 1/4 at a time and check top speed, water pressure and how it handles. After finding the best height for your rig you can revaluate pitch change or prop work needed
If you are willing to invest 300 for prop mods on top of the purchase price of a prop, I think you would find a 24 Fury would work very well for you
Mark Croxten would be the man to do the prop work, he is a board sponsor in the prop forum. Michael the moderator for the prop forum is a wealth of knowledge regarding props and setup
Were you trimmed up high when doing 50MPH at 5000 ? should have been
If numbers are correct and tach is accurate you have 26% slip (highly suspect)
Check tach accuracy by verifying with smartcraft or a digital tach
If tach is correct, you may have motor problems as well as propping issues
Try to borrow a 24 tempest to try and be sure to check the tach as a starting place

Thanks I will look at those things as well will be posting back tomorrow going to test the boat in the morning with a new prop.

[Ga_strat_273]

Update on motor. Unfortunately I found out the the #2 cylinder has no compression. Next question is do I rebuild or repower?

[lpugh]

I would highly recommend a fully dressed Mercury power head as this would insure the cause of that failure would be corrected most likely
Replacing the water pump, all fuel lines and bulb, servicing the lower unit and you should be in good shape for quite a while.
Rebuilding is a risky proposition because there so much more that could be wrong that caused it fail and by the time it is actually completed you could have as much or more invested than buying a dressed unit
The other big problem with building one is finding someone locale that can do it right, A lot people say they can, but very few can walk the walk
I live in Sacramento Ca and I do not know of any one that I would trust to work on my Optimax, especially rebuild it except myself and I would probably buy a dressed unit instead for several reason even though I have skill set and tools to do the job, A good machine shop may be required, that is good with these motors and they are even harder to find, None in my area. Automotive machine shops should not be working on these blocks, they do not have the experience to avoid critical mistakes

[JOE54]

dressed powerheads are for PXS motors you would need tuner also dont forget

[Ga_strat_273]

I would highly recommend a fully dressed Mercury power head as this would insure the cause of that failure would be corrected most likely
Replacing the water pump, all fuel lines and bulb, servicing the lower unit and you should be in good shape for quite a while.
Rebuilding is a risky proposition because there so much more that could be wrong that caused it fail and by the time it is actually completed you could have as much or more invested than buying a dressed unit
The other big problem with building one is finding someone locale that can do it right, A lot people say they can, but very few can walk the walk
I live in Sacramento Ca and I do not know of any one that I would trust to work on my Optimax, especially rebuild it except myself and I would probably buy a dressed unit instead for several reason even though I have skill set and tools to do the job, A good machine shop may be required, that is good with these motors and they are even harder to find, None in my area. Automotive machine shops should not be working on these blocks, they do not have the experience to avoid critical mistakes

Thanks for the advice! Where would be the best way to purchase a full dressed powerhead? Company or shop ?

[lpugh]

Bottem of post #9