502 MPI Mag/GIL Exhaust
#2
I've got 502mpi's with CMI headers and as far as I know, the ecm's are stock. I bought the boat used and never asked. The engines were bought brand new in 2000 with factory warranty, so I doubt they changed anything. No issues with running lean and they have about 350hrs on them.
#7
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Joined: Mar 2004
Posts: 65
Likes: 0
From: Denver, NC
I've got 502mpi's with CMI headers and as far as I know, the ecm's are stock. I bought the boat used and never asked. The engines were bought brand new in 2000 with factory warranty, so I doubt they changed anything. No issues with running lean and they have about 350hrs on them.
#8
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Joined: Oct 2005
Posts: 1,899
Likes: 20
From: Millstadt, IL
I do not have personal experience with this setup. But I know 502 mags run rich from the factory and leaning them out with better exhaust would probably be a good thing. If Griff say it works I would trust his judgement. He gives good advice. If in doubt install a wideband O2 gage. I have wideband O2 and it works perfect even a WOT.
#9
My 2000 502mpi's have over 350hrs on them with this set up. I ran the MWBP ppoker run this weekend with the sticks on the dash for 90% of the time for the first 31 mile leg of the run. Mine are also dry to outside the transom.
#10

Gils, CMIs, anything shouldnt cause the engine to run so lean you would hurt anything. I dont know how this idea/rumor got started!! Probably just helping the engine breath and burn better!



