525's...one runs normal the other
 

runs very rich. I was told that the computers would lean out after 20 hours. My starboard engine has but the port has NOT. I have 37 hours on them now. If I run the boat all day one engine will use 100 gallons and the other 120. The port engine oil will turn BLACK after just 2 or 3 hours while the other engine's oil remains very clean after 20 hours. Also the port engine is now turning 200RPM's less the the Starboard. Both engine turned the same RPM when they were both in break in mode. Any suggestion?

Re: 525's...one runs normal the other
 

I suggest that your mechanic call Merc Racing to get the latest news. There are several reasons that your motors are not running right...start with the cam sensor...some of the older models have failed. Also, there might be a problem with your 555 processor.

Re: 525's...one runs normal the other
 

You really need to check with your dealer. The 525's have had an upgrade done to the PCM. If you can rev the engine over 1500 rpm in neutral you have the old version. If you can not rev it over 1500 in neutral you have the latest version. Then you will need to see your friendly neighborhood marine technician.

Pwrbt33
Offshore Performance
1-877-GOFAST1
410-827-0200

Re: 525's...one runs normal the other
 

Thanks for the input. I was afraid of that. FYI My engines will run 3000RPM's in neutral

Re: 525's...one runs normal the other
 

well i have a 525 in a 288 sunsation and
it runs very rich smell fuel all the time .at 35 hrs it fouled 2 plugs
so my dealer called merc racing and they have my ecm and they are recalibrating it. i can rev it up in neutral so i will call dealer about that
i wonder if the dealer should change the oil again after the new calibration.

Re: 525's...one runs normal the other
 

Rotax

Does your oil turn black almost right away? Mine does on the rich engine.

Re: 525's...one runs normal the other
 

HEY HOW ARE YOU GUYS I'M CURRENTLY INVOLVE IN A PROJECT WITH SOME 525S AND I FOUND AFTER INSTALLING THE DIAGNOSTIC COMPUTER THAT ONE MOTOR THAT WAS WORKING PROPERLY WITH THE SAME TYPE OF PROBLEM HAD A BAD TPS THROTTLE POSITION SENSOR AND THE SECOND ENGINE HAD A BAD TPS AND IDLE AIR CONTROL VALVE. WE REPLACED THESE PIECES AND THE ENGINES ARE A TOTALLY DIFFERENT CREATURE NOW THEY IDLE TOTALLY DIFFERENT AND THEY ACCELERATE WAY BETTER.IF YOU DISCONNECT THE THE IDLE NEUTRAL SWITCH NEXT TO THE STAR. SIDE EXHAUST BY THE SHIFT LEVER YOU CAN ACCELERATE TO ANY ENGINE SPEED IN NEUTRAL.HOPE TO SHINE A LIGHT FOR YOU LAZ MESA WWW.MESABALANCING.COM

Re: 525's...one runs normal the other
 

In his case I would check MAP signal if it has one. If the signal is too low or there is leak the MAP will be telling the computer that you are at WOT all of the time. However it will set a code if the MAP signal is too low AND the TPS AND OR RPM indicates idle. I'm not real familiar with the 525 binaries but it seems like this is what is happening.

Roby

Re: 525's...one runs normal the other
 

guys
my ecm has been reprogramed oil was changed w filter due to black color
plugs too. that switch for neutral was disconnected on my boat.
at first i thought that was my problem nope.
getting the boat saturday will see how it runs this weekend.

Re: 525's...one runs normal the other
 

There is a new neutral switch that can be adjusted without taking everything apart. I just got mine and they should be installed soon. I had a problem where the brain (555) thought the boat was in neutral and wouldn't go over 3000 rpm. The new ones should cure that. I also had 2 cam sensors replaced. It seems as though I had an old style on mine.