Looking to install CMIs on a stock Merc 500 EFI, will the computer need to be re-flashed?

Thanks

what cmi's are you installing? 500efi's came stock with cmi e-top headers

I think the headers are CMI Sweepers, with built-in mufflers in the tips. The mufflers are switchable.

Thanks

No, it will not need to be recalibrated.

Thanks for the information.

Nope, just enjoy.

Should be a Etop style header if they are factory. Off Topic how does your 280 run with 500efi's?

The 500EFI question was a for a friend.

I installed a pair of rebuilt 97, Lingenfelter 502s in my Baja this spring. Engines were originally 540 horse EFIs that John Lingenfelter developed with Mercury.

I installed dart intakes and hollies.

Still working on props, hope to see high 70s. If I get it right may see 80, but this thing chine walks really bad.

Thanks for the info on the headers for the 500 MEFI.