Mercury ProMax 225

[OldSchoolBoats]

Hi Guys -
Back in April I bought a new to me 1986 Eliminator Sport Cruiser. It is outfitted with a 1996 Promax 225 EFI. Does anybody have any experiences / advice on this particular motor that they can share with me??

 

[BigSteve]

Hi Guys -
Back in April I bought a new to me 1986 Eliminator Sport Cruiser. It is outfitted with a 1996 Promax 225 EFI. Does anybody have any experiences / advice on this particular motor that they can share with me??

The Motor will go a long time if you do a few things

1. Make sure you upgrade the intake reeds. Mercury, used stock metal reeds. The stock ones will let go and ruin the motor. Fiber glass or carbon fiber reeds work much better and will not damage a motor if they let go.

2. Never start the motor unless it is fully in the water, replace the water pump assy once a year. I check behind my thermostats for small debris , and change the gear oil often.

3. Remove the prop after boating and check to see if you picked up any fishing line, a little line ruins gear case seals and leads to total gear case failure.

4. Fuel, always use fresh fuel 91 octane Chevron and Mercury oil
#1 reason for engine failure and voids all Mfgs recourse

5. Invest in a few good props. Matching the motor to the job is very important, Never Never, lug a outboard motor
We run a low 17-19 pitch for pulling tubes or skiers. it allows us to get the rpm up and have excellent throttle control over lower speeds we are running.

We run 24 to 26 pitch when we take a few people for a long cruise full of fuel

or light and alone 27-28 pitch in our 22 Daytona w /250 XS

6. This is a very important rule, you must run fuel and oil thru the motor once a month min.
Fresh fuel keeps the injectors clean and the oil mix keeps the crank and rod bearings coated.

#2 reason of engine failure injector plugged up

Outboards, will run wide open for years, trouble free if you do your part.

 

[138]

Very good advice for any optimax.

 

[Wicky]

referring to #2 and #6, I pull the lower unit during the off season and by doing so, I can run the motor once a month with no water in the garage during winter. I run it before it gets too hot obviously for a minute or so. Been doing this for 15+years on my 225 promax and she still runs like people in the ghetto during a drive by shooting.

 

[OldSchoolBoats]

The Motor will go a long time if you do a few things

1. Make sure you upgrade the intake reeds. Mercury, used stock metal reeds. The stock ones will let go and ruin the motor. Fiber glass or carbon fiber reeds work much better and will not damage a motor if they let go.

2. Never start the motor unless it is fully in the water, replace the water pump assy once a year. I check behind my thermostats for small debris , and change the gear oil often.

3. Remove the prop after boating and check to see if you picked up any fishing line, a little line ruins gear case seals and leads to total gear case failure.

4. Fuel, always use fresh fuel 91 octane Chevron and Mercury oil
#1 reason for engine failure and voids all Mfgs recourse

5. Invest in a few good props. Matching the motor to the job is very important, Never Never, lug a outboard motor
We run a low 17-19 pitch for pulling tubes or skiers. it allows us to get the rpm up and have excellent throttle control over lower speeds we are running.

We run 24 to 26 pitch when we take a few people for a long cruise full of fuel

or light and alone 27-28 pitch in our 22 Daytona w /250 XS

6. This is a very important rule, you must run fuel and oil thru the motor once a month min.
Fresh fuel keeps the injectors clean and the oil mix keeps the crank and rod bearings coated.

#2 reason of engine failure injector plugged up

Outboards, will run wide open for years, trouble free if you do your part.

That was exactly what I was looking for. Thank you for the response. I read that there was a recall on the ProMax for the ECU. Did this apply to the 1996 or is it more for the later years?? We pulled the motor up on MercNet and it said that the ECU was never changed when the recall was in effect.

 

[BUSTI]

The Motor will go a long time if you do a few things

1. Make sure you upgrade the intake reeds. Mercury, used stock metal reeds. The stock ones will let go and ruin the motor. Fiber glass or carbon fiber reeds work much better and will not damage a motor if they let go.

2. Never start the motor unless it is fully in the water, replace the water pump assy once a year. I check behind my thermostats for small debris , and change the gear oil often.

3. Remove the prop after boating and check to see if you picked up any fishing line, a little line ruins gear case seals and leads to total gear case failure.

4. Fuel, always use fresh fuel 91 octane Chevron and Mercury oil
#1 reason for engine failure and voids all Mfgs recourse

5. Invest in a few good props. Matching the motor to the job is very important, Never Never, lug a outboard motor
We run a low 17-19 pitch for pulling tubes or skiers. it allows us to get the rpm up and have excellent throttle control over lower speeds we are running.

We run 24 to 26 pitch when we take a few people for a long cruise full of fuel

or light and alone 27-28 pitch in our 22 Daytona w /250 XS

6. This is a very important rule, you must run fuel and oil thru the motor once a month min.
Fresh fuel keeps the injectors clean and the oil mix keeps the crank and rod bearings coated.

#2 reason of engine failure injector plugged up

Outboards, will run wide open for years, trouble free if you do your part.

WOW! That's a lot of maintenance. It's an outboard. Gas oil and go. If there was going to be that much work you might as well buy a V-Drive.

 

[OldSchoolBoats]

5. Invest in a few good props. Matching the motor to the job is very important, Never Never, lug a outboard motor
We run a low 17-19 pitch for pulling tubes or skiers. it allows us to get the rpm up and have excellent throttle control over lower speeds we are running.

We run 24 to 26 pitch when we take a few people for a long cruise full of fuel

or light and alone 27-28 pitch in our 22 Daytona w /250 XS

Steve-
Currently running a 22p five blade. I am hitting between 6300 - 6500 RPM and close to 65 MPH with the boat fully loaded and trimmed down. Is this a good all around prop to run on it?? I really don't have the extra scratch lying around to buy props. I also have a 23p 3 blade that I can use to, but my mechanic says that the boat won't plane for crap if I put that on. What do you think??

 

[hallett21]

WOW! That's a lot of maintenance. It's an outboard. Gas oil and go. If there was going to be that much work you might as well buy a V-Drive.

.

 

[Crazyhippy]

WOW! That's a lot of maintenance. It's an outboard. Gas oil and go. If there was going to be that much work you might as well buy a V-Drive.

Pull the prop after use, and an impeller/year is a lot of maintenance?

 

[BigSteve]

Steve-
Currently running a 22p five blade. I am hitting between 6300 - 6500 RPM and close to 65 MPH with the boat fully loaded and trimmed down. Is this a good all around prop to run on it?? I really don't have the extra scratch lying around to buy props. I also have a 23p 3 blade that I can use to, but my mechanic says that the boat won't plane for crap if I put that on. What do you think??

What mfg 22 pitch prop are you using ?

BBlades might have a couple props for you to try,

In the Mercury line, the Trophy and Rev 4 would be worth trying

Yamaha line the TXP prop (total excitement prop) !

Great props out of the box stock.

On the motors, Mid -section there is a sticker that gives max rpm @ hp
Your motor rpm seems a little high ? the tach could be off.

 

[OldSchoolBoats]

What mfg 22 pitch prop are you using ?

BBlades might have a couple props for you to try,

In the Mercury line, the Trophy and Rev 4 would be worth trying

Yamaha line the TXP prop (total excitement prop) !

Great props out of the box stock.

On the motors, Mid -section there is a sticker that gives max rpm @ hp
Your motor rpm seems a little high ? the tach could be off.

It is a Mercury Racing 22p 5 blade. Should I stick with that? From what I have read, it is a good all around prop for my set up.

 

[GregG]

It is a Mercury Racing 22p 5 blade. Should I stick with that? From what I have read, it is a good all around prop for my set up.

Post a picture of your boat from the back end.

 

[BigSteve]

It is a Mercury Racing 22p 5 blade. Should I stick with that? From what I have read, it is a good all around prop for my set up.

If its a Mercury prop it will have a part # on it. You may need to pull the prop

You may have a Mercury High five prop. However, they are in odd # pitch ie 19,21,23,

They work on some boats very well. lets find out what you have first and how it works :thumbsup

 

[bump]

Thanks! And what ratio do you mix at? It's usually 40 or 50 to one.

Do you use the Merc Quicksilver flush kit? Here with the drought I've been thinking of using a top of the line Rubbermaid trash can on wheels so the water people don't follow the river of water back to my home.

Again, a great post. I haven't been on here in a long time and had very little interest in this site other than a couple of people but a google search about this engine led me back.

The Motor will go a long time if you do a few things

1. Make sure you upgrade the intake reeds. Mercury, used stock metal reeds. The stock ones will let go and ruin the motor. Fiber glass or carbon fiber reeds work much better and will not damage a motor if they let go.

2. Never start the motor unless it is fully in the water, replace the water pump assy once a year. I check behind my thermostats for small debris , and change the gear oil often.

3. Remove the prop after boating and check to see if you picked up any fishing line, a little line ruins gear case seals and leads to total gear case failure.

4. Fuel, always use fresh fuel 91 octane Chevron and Mercury oil
#1 reason for engine failure and voids all Mfgs recourse

5. Invest in a few good props. Matching the motor to the job is very important, Never Never, lug a outboard motor
We run a low 17-19 pitch for pulling tubes or skiers. it allows us to get the rpm up and have excellent throttle control over lower speeds we are running.

We run 24 to 26 pitch when we take a few people for a long cruise full of fuel

or light and alone 27-28 pitch in our 22 Daytona w /250 XS

6. This is a very important rule, you must run fuel and oil thru the motor once a month min.
Fresh fuel keeps the injectors clean and the oil mix keeps the crank and rod bearings coated.

#2 reason of engine failure injector plugged up

Outboards, will run wide open for years, trouble free if you do your part.

 

[GregG]

WOW! That's a lot of maintenance. It's an outboard. Gas oil and go. If there was going to be that much work you might as well buy a V-Drive.

His advice was excellent and that's not a lot of maintenance if you want the motor to last.

 

[GregG]

An old thread but a good one. Promax 225's are EFI's and are a great motor, the only thing to be careful with is the auto oiler. Merc fixed that problem on the 225X that replaced the Promax in 2002. :thumbup:

 

[Outdrive1]

People don't get how important matching a prop to an out board is. If you're lugging the motor with too big of a prop, it basically changes the timing and the motor detonates. The piston doesn't make it all the way back up because of the load on it. It's not like an I/o car motor. It's light and it doesn't have a lot of mass spinning with it so the load slows the crank down.