Problem with 225 Pro Max

[wired]

So I'm guessing that the Pro Max is the single air opening fuel injected rig without the air pump and fancy ECU but with a nylon oil pump drive. When I saw the model year, I was envisioning three two barrel carbs. Sigh.

The 225 Pro Max is a laser injection 2.5 liter steel bore Mercury. Pretty close to the 200 fishing motor but with a 260 exhaust divider, different coil holders and the 7 petal fiber reeds and slightly higher compression (37 CC heads ) and thinner rings on the earlier versions. Same fuel management system as the 2.5 fishing motor 150/175/200's except for the 7 petal intake. It does use a higher rev limiter ECM and generally come with the heavy duty lowers. The late blocks like mine use the rod slot ported sleeves like the 240 sport jet but Pro max uses head gaskets. Most dyno tests on the 225 ProMax's show closer to 250 HP at the prop in stock form.

This is mine with a spacer to unshroud the outer reeds and a Brucatto ACU.

 

[wired]

BTW if you do get through troubleshooting and you want to get past the whole VST thing and mount a boat mounted pump 260 style this is what it would end up like...

 

[nickhedstrom]

How do I know I got the right voltage regulator? It worked great for 1 full day then the next day I had this problem.

If the fuel pump or fuel pressure regulator were bad it would effect me on all cylinders. Its 3 of them that look diff after idling awhile. 1,4,6 look real clean and 2,3,5 look black.

It idles bad and misses all thru the RPM range up to 4500 then thats all I get.

BTW my prop was completely black after idiling with muffs on, I was testing spark for 15 minutes.

 

[nickhedstrom]

Also it would start like there was no propblem then act funny after runnung a bit.

 

[wired]

Did you download the manual? The voltage regulator doesnt really have anything to do with the spark.

If you are fouling plugs at idle its not going to be the high speed coils fault. Do you have a DVA adapter for a multimeter. Buy one or build one. You are going to need it. You need a fuel pressure gauge with a adapter for the schrader valve on your VST's voltage regulator.

 

[nickhedstrom]

Yes I downloaded it and it looks real handy. Where do u get a DVA adaptor?

 

[wired]

Yes I downloaded it and it looks real handy. Where do u get a DVA adaptor?

http://www.usatoolwarehouse.com/usatoolwarehouse/ESI-640.html

 

[kct11]

Did you ever get this sorted out?

 

[nickhedstrom]

Yes, the motor was going south, did leak down and had to bad cylinders but my spark was good. Soooo $3200.00 later I had it rebuilt and then some. So now the painful time of break in.

 

[kct11]

Bummer. At least you got it done in a timely manner.

 

[nickhedstrom]

Yep, basically 1 week

 

[Schultzimport]

Anyone Know what my pro max issue could be.
Leak down test good, Brand New Trigger., Rebuild was done recently, Never had motor full speed. Idles beautiful out if the water. Revs Perfectly, Once it's in the water, it's a dog, won't pass 2k RPMs.
Some one told me the Reeds could be Cracked.
I've got 7k into this motor and still haven't even taken this boat out..
Please I need help

 

[sonicss31]

Not to many ProMax gurus on here anymore. Try to ask questions on Scream and Fly forums.

 

[caliburn]

Anyone Know what my pro max issue could be.
Leak down test good, Brand New Trigger., Rebuild was done recently, Never had motor full speed. Idles beautiful out if the water. Revs Perfectly, Once it's in the water, it's a dog, won't pass 2k RPMs.
Some one told me the Reeds could be Cracked.
I've got 7k into this motor and still haven't even taken this boat out..
Please I need help

I dont know injected out boards so i be guessing but i can tell you this if your reeds were as bad as you think they are you would be getting massive blow back out of the intake as any reeds keep the gas in the engine bad reeds would alow gas blow back,
Dont know that engine but i do know like on my two stroke and any jet ski to get your idle right it has to be in the water under load as you can have perfect idle out of the water but once under load it will run like its retarded.

 

[Schultzimport]

Thanks so much for the advice