jeff here's their system http://www.painlessperformance.com/w...rchField=65253

msd sold the rites to painless,i have the engineers cell phone number in my rolodex some place..ill try and find it and pm it to you..

Msd is coming out with a all new system..

There are a few reasons to use a Mefi. First, it has nothing to do with Merc. As a matter of fact, Merc. never used a Mefi 4 on any engine. However, the engine can still be serviced by a Merc. mechanic. There are Merc. shops where ever there is water. I don't know of any Big Stuff mechanics around. Merc. will not tune an ecm for you. You will have to have a tuner calibrate the ecm. There are several of us around, or you can use an aftermarket system like Mefi burn.
Next, the Mefi has knock protection. The Big stuff doesn't. That is WAY more important than running an O2, which the Mefi can also do. I wouldn't want to run an O2 in a boat full time. I use them for tuning and then they come out. There is no need to keep them in. Not to mention, they are highly allergic to water and will crap out at the first sign of water on the sensor.
These are a few reasons why I strictly use the Mefi. Everyone has their preference and this just happens to be mine.
Eddie

Not an boat application, but I'm running the new Holley HP system and its awesome. The self-tune function is awesome. Its has knock protection. The Dominator version can also do dual widebands.