I have a new to me boat with twin HO's, 02 vintage. Merc confirmed that my p/n s/n pcm's were set up too rich and that's why my transom gets dark so soon.

I was about to pull them and send them in for recall- I mentioned it over on HB and someone said he thought he remembered people actually losing speed/power when this happened.

It's hard for me to imagine merc going too lean on the recal and it seems that going closer to "just right" from too rich should actually help??

Any real world experience with this?

I had my 2003 CPUs replaced under Mercury Warranty to lean them out.

I have not experienced any power loss, and even if I did loose a tick, I would not mind due to the EXTREMELY easier cleaning of the transom.

No loss of power when they changed mine...Fixed the sooting problem.

Catitude, I was the one that posted that on Hotboat. My Merc. certified mechanic was the one that told me about the possible power loss. He said he has seen it, and the problem is, that if you have your PCM reflashed, and you don't like the results, there is no going back. Merc. will update, but if you don't like the way it performs, you are out of luck, as there is no way of loading an older version back in. When Hotboat gets back up, I will PM you the mechanics name. He is out here in Lake Havasu, and you can call and talk to him before making your final decision.

Thanks, I will call him