merc trouble

[Bloomer]

I hope this is not worse than it is, would love to hear any ideas. The trouble started on thursday. This is a 1996 Merc 225 EFI. I have owned this motor for 6 years with never a hiccup. On Thursday it started running really rough, tough to start. I usually plane in 4-5 seconds, Thursday it took me half the lake. It almost felt like it wasn't running on all cylinders. Then I would finally get on plane, I typically run 65-70 WOT, I couldn't get it over 45. When I got it off plane it would die. So I got it back to the ramp, I hoped it just wasn't getting enough fuel, So I changed the fuel filter, and the in line filter over the fuel pump, making sure there wasn't a clog in the fuel line. I fired it up in the driveway and it was still running rough. When I was running it in the driveway, the top two cylinders got scalding hot very fast, the bottom two cylinders were ice cold. But the impellor was pumping plenty of water, very strong stream out the back, also ice cold.  I then took all the spark splugs out, they were all wet and all getting gas, whether or not they were all firing, I don't know. But when I shut it down, it started spitting out a lot of gas with the water out of the exhaust through the prop, and from the drains over the lower unit--a lot of gas. I ran the motor for 15 minutes and went through 10 gallons of fuel...idling in the driveway...My only thought at this point is maybe I have a leak in the fuel line and it is not getting the pressure? I hope this is a cheap fix, but at this point it is not looking good, I have not had this to any mechanic yet.....just looking for any thoughts on this......

[bassmandan]

it sounds like what my 200 EFI did a couple years ago, lost a couple pistons due to a problem in the ECU box, it cost me a little bit of money to fix  , but if you want to get it looked at i suggest taking it to North Bay Marine at 23 and Jefferson if you are nearby there, i dont know where you are located.

[Lightningboy]

It could be the ECU.  Could also be the stator.  Or with the rate of fuel you're dumping, it could be a fuel rail leak.

You really need an expert to look at it.  Sorry dude.

[Bloomer]

Bad stater, and a bad head gasket. Going to be kind of pricy.

[Lightningboy]

Any way we can help?  I do have the merc shop manual for that motor.  I'll take a look and see how hard it is to do.

If you can turn a wrench, maybe I can talk you down from the tower...

[Bloomer]

Well I can get myself by with simple stuff, but something electronic like that, probably not. The part itself(stator) is $473.00, believe that is what I was quoted. The head gasket, was 8-12 hours of labor, so I was told. That one I doubt it.

[Lightningboy]

Um, no offense to any outboard mechanics, but how can a head gasket take that many hours of labor?

Pull the hoses.  Heat up and remove the temp sensor.  Loosen the head bolts.  Scrape gasket surfaces.  To do it right, have the head trued at a machine shop.  Bolt on head/new gasket.  Set temp sensor in epoxy.  Install thermostat/hoses.

Yeah, time consuming, but I can't see more than 4 hours labor.

[Bloomer]

I have no idea, that's what I was quoted, definately looking around before I fork over that kind of money.

[LAPORTE]

the stator is under the flywheel, It should be plug and play.. Im just not sure how a bad stator plays into dumping fuel .... it must be a ecm deal .. be sure to check around.. Replacing the head gasket is a snap like lightning said it should not take more than 4 hours top. I'm thinking book time is around 2 hours guessing

[Lightningboy]

Just checked my manual.  Stator removal is pretty simple too.  Unbolt the flywheel, loosen the belt tensioner, remove belt.  Unbolt timing pointer.  Remove flywheel.  Unbolt stator.  Bolt in new stator.  Bolt on timing wheel, and pointer.  Retighten belt.  Go for drive.   

The bad stator sends a false signal to the ecm, screwing up the fuel curve.  EFI motors are great, but one sensor goes bad they get temperamental.

[LAPORTE]

Sounds like a easy fix If indeed this is the problem causing the issue... 

[champion_206]

did you check fuel pressure, sounds like a bad fuel pump diaphram  dumping gas in the motor ( crankcase) unless I am missing something else, if its a stator your  motor should not burn that  much gas if its bad

[Bloomer]

got the new stator put in, did one lap, shorted out that one too. Ran great, then died. As of now, maybe looking at one of the ECU's. Pretty sure it is electrical, the bottom two cylinders have no juice going to the plugs at all. Top 4 are fine.

[customfishn]

Check your reeds, they are stainless steel and if they break they will flood the cylinders.  I have seen that problem before and when you clean the plugs and run the motor it will run fine for a little while.

[Bloomer]

Still waiting on a new stator and an ECU. Should know by the end of the week if this is the cure, going on 4 weeks out of the water....

[dartag]

Did you take it and have the codes read.   That may tell more of what is going on.  I want to get mine read but North Bay has a 2 week or longer wait to get in.  Probably wait till fall.

[Bloomer]

If this doesn't fix it, I'm taking it to a merc dealer, been out of the water since the first weekend of June, the tourny season is pretty much shot anyway.....

[customfishn]

Um, no offense to any outboard mechanics, but how can a head gasket take that many hours of labor?

Pull the hoses.  Heat up and remove the temp sensor.  Loosen the head bolts.  Scrape gasket surfaces.  To do it right, have the head trued at a machine shop.  Bolt on head/new gasket.  Set temp sensor in epoxy.  Install thermostat/hoses.

Yeah, time consuming, but I can't see more than 4 hours labor.

Head gaskets dont take that long, on a 225 efi there are 16 head bolts and no gasket they are o-rings and I can do them in about 15 minutes

[Bloomer]

OMG, this is about the simpliest, just most brain dead solution to this whole problem. All of this was caused by a torn diaphragm in the low pressure fuel pump. After getting the stator repaired and the pump, cost was $266.31. Out the door, oh yeah and the 45 gallons of gas to figure it out, still scratching my head on how this took 5 weeks to get an answer on....