225 ficht plugs not looking so great

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
hi guys so in the last month I have been posting lots of questions trying to get some rpm's out of the motor & seeking for a problem, first I went towards the prop,lifting motor,plugs,ect.<br />After pulling the plugs out today I really think there is a fuel trim problem.<br /><br />I put a set of new plugs in 10 hours ago when I pulled them out today they were so black i don't even know how the motor runs. after i pulled some info from the motor. Coming up with 1 intermittent code (code 28) shift assist circuit.which I have searched and found very little info on it. any info on that would be great.<br /><br />next questions i have, is there anyway to datalog a/f or to find out why its running so rich? I just cant see it being normal for the plugs to be that black.<br /><br />some other info.<br /><br />225fpxssc<br />sw/ver-3030070<br />sw/pcn-27757<br />hours-387<br />max rpm I have seen-5200-5300<br />last time code 28 was @371<br /><br />Thanks again <br />Chris
 

muskrat

Chief Petty Officer
Joined
Apr 13, 2004
Messages
445
Re: 225 ficht plugs not looking so great

WHAT THE COMPRESSION.DO YOU CHECK ANY OF THE FUEL TEST IN MANUAL.CODE 28,CHECK SHIFT ROD MOVEMENT WITH SHIFT CABLE REMOVED SHOULD MOVE FREELY.
 

WillyBWright

Fleet Admiral
Joined
Dec 29, 2003
Messages
8,200
Re: 225 ficht plugs not looking so great

Sooty plugs are actually normal. Merc Opti's do it too. It's why they use such expensive sparkplugs. Sooty and wet would indicate a rich fuel mixture. It has to do with a layered fuel charge caused by multiple direct injections per burn.<br /><br />You need the software and a computer with all the right connections to access the data and there is no way to change the fuel mapping without equipment reserved for engineers and regional service reps. But if there's a problem with fuel delivery, it's almost always a sensor problem.<br /><br />A word about those sparkplugs. Don't measure or adjust the gap. Eyeball them and adjust (very carefully) only if it's way out of spec. The electrodes are very easy to damage. Putting a tool in there can ruin the plug before you get a chance to use it.<br /><br />There's also a procedure called Sparkplug Indexing. Locate where the ground electrode (the hook) meets the plug base. Mark the porcelin on the upper part of the plug 180 degrees from that spot (a sharpie works well). You want the opening to face the piston if possible, but 90 degrees either way is okay. You mostly don't want it to directly face the head. It helps prevent fouling. The sparkplugs still need to be tightened as much as you would any sparkplug. So you won't know where it's facing until it's tight. You may have move sparkplugs around until you get them all facing the right way. But it's almost always possible with a single set of 6 plugs.
 

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
Re: 225 ficht plugs not looking so great

ya,i have done all the plug indexing stuff when i put them in. would that code 28 cause any real problems?
 

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
Re: 225 ficht plugs not looking so great

can anyone else think of why im not getting the rpm i should be???
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: 225 ficht plugs not looking so great

If the motor is only reaching 5300 rpm it is overpropped or out of spec. The recommended operating range is 5500 to 6000 on that motor. Have it checked out and possibly re-propped correctly.<br /><br />Be sure the exhaust sensor has been removed and inspected for carbon plugging.
 

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
Re: 225 ficht plugs not looking so great

first thing is where can i find the exhaust sensor? next is i have tried another prop (19") which the boat came with a 21" , as well as lifted the motor with not sure great luck, any thing else you can think of?? would i get a code is the ehaust sensor was pluged?<br /><br />thanks<br />Chris
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: 225 ficht plugs not looking so great

No code will show.<br /><br />Follow the small hose from the EMM (computer) down to the stb. lower adapter plate under the powerhead. You have to remove the sidecover bolts and carefully pull the stb. side away for access. Remove the hose clamp and unscrew the fitting. It is is severely plugged up, as it probably will be, just replace it. The newer ones are more foul resistant.
 

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
Re: 225 ficht plugs not looking so great

anyone have a part number for the exhaust sensor? my dealer is not the brightest.<br /><br />Chris
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: 225 ficht plugs not looking so great

Originally posted by Chris Green:<br /> anyone have a part number for the exhaust sensor? my dealer is not the brightest.Chris
#5001298 about $38.95
 

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
Re: 225 ficht plugs not looking so great

i called my evinrude dealers gave them the part number they said it came up as a nipple assembly.<br />is this correct>?
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: 225 ficht plugs not looking so great

Yep, the factory parts people have contests to see who can name something completely different to what it actually is.
 

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
Re: 225 ficht plugs not looking so great

ok so i goto pull it off today and just like you said it was pluged up, i just took a drill bit (by hand)and pulled out the carbon then brake cleaned like new. I had a question about it what does the sensor do? obviously it reads exhaust gas but what is it reading a/f,EGT,Psi? also the what looks like a check valve on the same line leading to the ecu does that need to be cleaned?<br /><br />Thanks<br />Chris
 

paulie0735

Chief Petty Officer
Joined
Dec 6, 2005
Messages
463
Re: 225 ficht plugs not looking so great

Chris, I'm not sure that cleaning the sensor is gunna work for you. Many EFI sensors are very 'sensitive' to chemicals, brake cleaner is very severe and may well have rendered your sensor useless. E.g. the use of silicon sealant on an inlet manifold can destroy some types of exhaust gas sensors the first time the engine fires. <br />You would do better to heed the advise from people who know what they are talking about (seahorse is one of those people)
 

Chris Green

Seaman Apprentice
Joined
Sep 18, 2005
Messages
34
Re: 225 ficht plugs not looking so great

can someone please explain what the sensor actually does? I appreciate your reply to my post, but how am I suppose to heed the advice from people who know what they are talking about when you haven't explain anything that I inquired about in the previous post?
 

seahorse5

Rear Admiral
Joined
Jan 24, 2002
Messages
4,698
Re: 225 ficht plugs not looking so great

The sensor "reads" the exhaust back pressure and delivers that info the the computer. The black round thingy is a diaphragm assembly that amplifies the differences in backpressure and protects the computer from the direct heat and corrosive gases of the exhaust.
 
Top