I spoke with Dustin in great detail before sending him the PCM. I am pretty sure he flashed it with a Stage 2 program designed for the 496 Mag (non-HO). But I will certainly follow up with him again to be sure. I will say this, the motor runs a whole lot stronger after the Whipple Stage 2 flash. If it was a choice between light soot (now) w/Stage 2 or No Soot and go back to Stock PCM Flash, I will choose the Stage 2 every time. Even though the soot is a pain in the ass, the boat has so much more low-mid-range torque now. No way I would go back.... (This is the 3rd season with the Stage 2 Flash).

all right then ,,leave it alone and use it,,you have been going round and round with this for a while now,,


the stage 2 is a upgrade to the HO program not the Mag..you have the wrong cal in there,,to make it run right you need to install a HO cam and drill out you throttle plate idle bleed hole from 3/16 to 1/4,and the stage 2 requires and different thermostat,but if you like it then leave it and dont worry about what the plugs look like..
been doing this a long time and have been round and round this issue,,

Boatnt that is incorrect information. Whipple has a Stage II flash for both Base and HO PCMs. See below for the email discussin between myself and Dustins this morning..

My email:
"My name is Bradley Lynn and a few seasons ago you did a stage II flash on a PCM for a 496 Mag for me. I originally had you do this because I had a lot of soot and wasn't certain of timeframe Mercury had given me. Anyway, after talking with you we ended up going with stage II flash. You mentioned I would see some soot still as it was tuned for premium fuels. Well I have still been fighting a lot of soot. One of the issues was a leaky intake gasket that was pulling oil in under high vacuum. Once I fixed the gasket I still saw a decent amount of soot, but not greasy as it had been. It appears that may have led to dirty injectors, which I think I have gotten straightened out. I now still see a little bit of soot, enough so that I have only been running 90 octane ethanol free, which does cut down on the soot a bit. Since I don't run hard, I don't think I am damaging it by running 90, am I?. Anyway it was mentioned in a thread I have someone thought the Stage II flash was only for the 496 Mag HO. I have a 375hp 496 Mag Non-HO. Is there a way for you to verify the flash that was put on my PCM is correct for the Non-HO motor. It runs so good I assume it is correct, but I guess it couldn't hurt to check. DO you need the serial number or can you look it up by my name? Also can you confirm the fuel and plugs it was calibrated for? Pretty sure you said 91 or 92 Octane... Any help you can lend would greatly be appreciated."

Dustins Reponse:
"Thank you for the info. 90 octane will work under most conditions, 91 is better but most of our 91 has 10% ethanol and run hotter in the combustion. The 90 octane should have no issues.

We have cals for both the Base and HO models. I don’t have your PCM flash serial number or date, but if it came as a Base, it would be a base. The motors, with the wrong file, run just awful."

If I had a HO Stage 2 flash on a base motor, and Dustin says they run awful, I doubt I would be seeing GPS speeds in excess of 70........ Which I have done a few times this year. So there is a Stage II flash for the 496 Mag Base Engine, and it is what I had Dustin put on it. I am also running a stage II 120 T-Stat as what was purchased when Dustin Flashed My PCM. So I am confident the PCM can be ruled out at this point.

Your right I have, and the problem still exists..... That's why I am posting in hopes someone else has an idea... The PCM is correct, Doesn't show any faults, yet runs rich beyond what it should. I have addressed Flame Arrestor, Intake Gasket (which was at fault for the greasy soot, no longer an issue) and yet I still have a problem. So I posted a pic of the plugs in hopes someone might notice something outside of the obvious, like maybe one plug lookes a little different (maybe narrowing down the search to a side of the engine or even a cylinder or two that looks like it is firing a bit different). I have done compression checks and leak downs and all are well within spec, again boat can run full RPM and expected Top Speeds without issue.

firing issue (weak)....i just went thru this on my boat....for me i changed distributor and it fixed the problem

496 uses a crank and cam sensor and 8 coils no distributor

ok,,if you say so....

I didn't say so... Dustin @ Whipple did. So I will go with his knowledge of his product/work...

as Boatnt said, the 496 is distrubitorless.. It has a 1 coil per cylinder. I wish there was something that stood out like one really bad plug, then I could pursue maybe a bad wire, or bad coil. Thats why I posted the picture of the plugs, hoping something would stand out to the experts that maybe the normal untrained eye didn't see...

i understand it has no distributor. im only saying that the exact thing happen to me and the plugs look identical to yours and it was my distributor. i chased it for 2 months.