Updated ecm's for 496 / Black Transom
 

Just got off the phone with my dealers service manager. Her informed me that Mercuiser is providing an update to the ECM to eliminate the Black Transom.

Anybody here the same or have any more information?

A friend of mine had the same problem,got a new ECM from his dealer(updated from Mercury)works great!No more black transom. Bob

Assume your talking about soot?
My 375HP was terrible for first 25 hrs..somewhat better
now, but still soots..Is the new ECM for Mags and HOs?

My 496HO cleaned up after 25 or so hours as well.

Should we be expecting the transom to stay perfectly clean.

still after 210 hrs.
 

Much better than it was in the begining,
but still get it every time I go out. I clean it
with simple green. I warm my boat at 1200
instead of idle, seems to help, I believe its
getting too much fuel when cold and the higher
rpm seems to burn it. This was suggested by
a tech. I wonder if I'm too late to get mine done.
John

I also had the update done, no more black soot on transom. The motor is a 496 HO. I sent it on Monday and got it back on Wednesday.

Wheres it located and how do u replace it??I guess u have to remove old one first?

My friends 496 was a mag.He almost sold the boat because of the soot.*****ed one more time to his dealer and "presto-chango" new ECM, no more soot!Mercury said he'd be happy and he is. Bob

What year or ser# engines or ECM's does this apply to?...If there is a leaner running update, I want to know about it! I'll take any crispness I can get, any any RPM

More info please, Snopro did you send the ECU to Merc. yourself or did the dealer. I will get mine out tomorrow if I can. I just got done cleaning again from the weekend and the soot is terrible. 35 hours on it now.

Merc is handling this as a warranty issue on the ones we've fixed. I believe you'll need to have a dealer handle it. If it's out of warranty then I would contact Merc's customer service and see if they'll help you out. We just picked up a couple of '04 Nordics with the 496's and they seem to run pretty clean.

Voodoo, an authorized merc dealer has to send it in. Mine was out of warranty but there was no charge from merc. No black soot at all!!!!

Just got confirmation today from my dealer a new ECU is on the way for exchange. Hopefully it will get here for the weekend so I don't have to clean all that $hit off after 3 days of running.

BTW, has anyone tried a K&N filter yet. The stock breather looks pretty unrestrictive, but I ordered one anyway. 59-5005 bolts right on and is only $60.00. It is listed on the K&N site for marine applications. I have a connection at K&N and got a smoking deal on one to try.

Stock flame arrestor flows better air. Only thing K&N does is keep dirt out. I don't see much dirt out on the lake. I had one, didn't see any difference, went back to my stock one.

I should get my new ecm from my dealer any day.

Had mine (mag) done over weekend...
Sounds better, picked up 2 mph and no soot...
Dealer knew nothing about it and Merc apparently played dumb till I told them to look at this site.

I installed my new ECM last Friday. I have no more soot and no noticeable performance change. I did have a little more top end over the weekend, but that's mainly do to the cooler weather here in the northeast.

Looks like winter may make an early return. :( :( :(

For those that have tried the new ECM did the soot problem go away right away? I remember with the original one that the program was setup to run rich for several hours until the engine is broken in. Then it would lean out. Since you have a new ECM I would assume that it doesn't know your engine is used and would start this procedure all over again. Therefore you are running rich until it reaches a certain number of hours. Have any of you experienced this or know if that rich period is eliminated.

Rick

I had 80hrs on the engine and a lot of soot every time I when out. I installed my new one and the next day I when out for a three hour run and no soot what so ever.

Not sure how the new ones work when motors are new.

Bcoffield,
That is what I am hoping for. Hopefully mine arrive this week. Thanks for the reply.

Rick

O.K. fellas...here's my story. 496 HO's. So @*#kin' rich the stink of raw fuel is about giving me a headache. At 3K cruise it's terrible. After idling a few minutes and shutting off, it's so bad I'm afraid the boats gonna blow up! :eek: I have looked for leaks/raw fuel in the bilge it's so bad! I run the blower alot! It doesn't stink of fuel in the bilge so much...but the fumes in the cabin can be unbearable! Even an hour after docking (tavelling thru the hull getting trapped in the cabin). The tank vent(s) ARE plumbed to the hullsides as they push air when I'm filling. I have changed engine oil @ 6 hrs 'cause it was black . Fresh oil black (gasoline contaminated my guess) in just 2 or 3 running hours! 17 hours on the engines now. Boat runs well though I'm getting a little tach jump (both sides) @ 3000-3500 rpm which may suggest dropping the occasional fuel soaked plug! What do you guys think? These are '02's in a 353 Formula just bought new. :confused: :confused: Anybody have the raw fuel stench along these lines...under the circumstances we're discussing? Not to mention the boat seems pretty hard on fuel consumption. It's not my first twin engine boat and I had floscan in the last one, and Formula's perf report with fuel burn specs for this combo in hand. She drinks :crazy: .

Had new ecm's put in last weekend, no more black soot. NONE! It is finally clean after a run. Not sure about performance though, didn't really open it up.
Midrange punch seemed to be improved. My tech seemed to think there would be an increase in performance.

Rippem
Only problem i had on the mag was SOOT..Which cleaned up considerable after 50 hrs..Oil did get black rite away and was changed..After ecm swap no soot at all..Dealer said merc told them the problem was only on mag not HOs, I gues we know better..

Mine is much better since the change. I still had some soot after 3 days of running but compared to what was there before it was nothing. No performance change other than the fact that it was 20 degrees cooler than the last 2 weeks. I suppose that could have helped the soot as well.

Had the same soot problem on my 02' 496 mag. Called Merc and was told to take it to a dealer and they would send it in for reprogramming. Went to a local dealer who had not heard of the problem. They called Merc and a new PCM was sent out that day.
Date on new PCM is 8/29/2003. Part # 865364-001.
Time will tell if it helped the soot problem and what it did (if anything) to performance.
Anyone seen a service bulletin on this?

I was told there was NO service bulletin or recall of any kind...Thanks to this site we were able to get Merc to fix..

Is anybody other than merc doing this?


I know its a 4 yr old thread, but Im getting tired of cleaning now.

I've got an '02 496HO that still soots up the transom big time! I have a Raylar BCK103 kit on it with Whipple's Stage II ECU calibrations. Had hoped that Whipple's calibrations would take care of the soot problem, but no luck. I think they will do custom ECU programs (for a price) you could try them. I've also looked into Arizona Speed and Marine (they offer ECU programming also), but don't know much about them. I would love to lose the soot, but I don't want to risk leaning out the engine - it's running great and the spark plugs look good.

Were the only ones that can work with the PCM 555 on the Mercury engines. It's pretty hard to totally remove the soot, especially on some boats. We run 14:1 air fuel, far more spark and coil energy, yet it will still be there. Our Stage1 has less soot than stage 2 because it's lower hp and not as agressive for power.

Dustin

Dustin,
Can engine operating temperature affect how much soot is produced? I have a low temp thermostat (engine runs around 140 most of the time), I have been told that it might be too cool and the computer is going into "cold start enrichment mode" - causing some of the soot. What do you think? - Thanks.

Lower temp will typically increase soot, but also allows for more timing/compression which typically makes more power. The computer has temperature enrichment decayed out based off of time running and temp. Therefore, at 140deg F, even after firing, it only gives a small amount of fuel for a few seconds. At 60, it gives more fuel for longer periods. Thats is certainly not an issue. If it runs 160-180, it will have slightly less soot, but will be much closer to detonation, and if it detonates, it will use more fuel, as it uses fuel to try and stop detonation, along with timing retard. Now this does totally depend on how the driver drives the boat. If your running hard, the engine needs to run richer or closer to ideal AF for peak power and to keep cylinder temps down. If you cruise a lot, or have a boat that doesn't require lots of power to stay on plane/cruise, then it would be leaner and potentially have less soot.

Thanks,
Dustin

So putting back the stock thermostat might increase the risk of detonation (with the compression ratio of Raylar's heads, and the Stage 2 calibrations)? What else do you think can be done to substantially decrease the amount of soot. My brother-in law has the same boat but with a 540 and has no soot problems at all (he's running 750hp on the dyno). I often get a strong fuel smell from the exhaust when going through no-wake zones (stronger than my previous boat - a 502 carb).
Thanks
Bruce.

More Clean time
 

Guys:
As I have posted in the past, a lot of the black soot you are seeing on the back of the boats is from the fuel itself.
We've actually done some testing on the dyno and what we see is the black soot in the dyno headers after testing even when we have leaned the air fuels to a point of detonation and power loss. Most of this soot seems to be from the various fuel blends for the new lower emmisions fuels (HA!)
and when we used base (testing) fuels the soot disappeared.
On various hull designs the transoms especially extended transoms have a negative pressure area behind the boat at the transom that can pull the exhaust back to the boat and give it more time to deposit the soot on the transom.

My suggestion on the 496 is not to run 91 or higher octane unless you running a supercharger. On a stock or our Raylar 496's it is not needed and in fact its slower burn rate will create more unburned fuel in the exhaust and create more soot.

Just some info here to help explain the conditions for todays fuel soot!

Best Regards,
Ray @ Raylar

Ray, any info on the 2007 program yet. We had to pull the water pressure sensors and plug them off to keep the motors from going into gaurdian mode. As soon as the water pressure sensor hit 43 psi we would get an alarm an the motor would go into gaurdian and drop the rev limit down. Removing the sensor and leaving it plugged in and pluging the cooler has worked for now but it is a temporary fix.

Your water pressure should not be running that high in actuality. Check the system with another sensor or a mechanical guage and if the pressures are that high start checking your system for a restriction somewhere in the raw water system. I am surprised at those kind of pressures that the pressure relief valves have not been opening and dumping a lot of water in your bilge.

Best Regards,
Ray @ Raylar

No. The water pressure is not that high. When the key is on engine off the value for the water pressure is 28psi,then when you start the boat it goes to 32 psi. (So it is actually 4psi at idle) Since the new program you installed, the starting water pressure is 28psi! It is a programming issue that needs to be addressed.

I was having a major soot issue on my boat as well. The problem was there stock, then with a Raylar/Stage I and Raylar/Stage II. After explaining my problem to Ray and Dustin, I sent the PCM back for another tune (along with all my data). I now only run Sunoco 89 as well. A few runs later, the soot is gone! I don't know if was the tuning or the fuel I'm now running, but I'm not going to change either. :D

One more thing, I have a FASS 02 monitor @ the helm which reads both manifolds and I always know my AF.

I don't know who I should be thanking more - Bob, Dustin, Ray, BES or Plane Silly. Thanks guys! :D

Hey guys what I get a little soot too and was wondering what products are out there to remove the soot without removing the wax / shine and damaging the surface.
Is it at all possible to have a completely clean white transom after a day of operating??

I trailer my boat, so everytime I get home from the lake I wash the boat - doesn't remove the soot, though. I've found that Meguiar's Boat Wax takes the soot right off and leaves a coat of wax on the transom. If the soot is particularly bad I will use Meguiar's Mirror Glaze 45 Boat/RV Polish first (dissolves the soot right off), and then wax with Meguiar's Mirror Glaze 56 Boat/RV Pure Wax. The transom comes completely clean - no residue left behind at all. I have noticed that over time the gel coat has started to yellow a bit from the soot, not really noticeable.

Do you use the low temp thermostat that comes with the Stage 2 kit? What kind of engine temps do you run at? I have the Raylar 103 kit and Whipple Stage 2, and the transom soots up big time. I've been running 91/92 octane, but will try 89 instead. I'm wondering if the low temp thermostat is also adding to the soot problem (my engine runs 140-150 F). Did Whipple do a custom program on your PCM? Did they say what kind of changes they made to it?
Thanks
Bruce

I'm using the stock stat. I'm told you don't need the low temp stat and only need 89 gas with aluminum heads. Yes, Dustin did a custom program based on all the data I sent to him. I recorded the A/F, fuel pressure and manifold pressure @ 500 rpm increments. It's very difficult to get it tuned just right from 3,000 miles away, so it took a few times. I really don't know exactly what he did to it, but it works. :D As far as the gas goes, if you have Sunoco in your area, give their 89 a shot.