Hi

Is it possible to instal a closed cooling circuit on a MERCURY 500 EFI ?

If you have realizes this evolution, some photos, with supplier, satisfied ?

If so, lateral position feasible ?

Thanks you in advance for your leads

Absolutely possible. I did it on mine a long time ago, and it's even more readily available now.

Hi

Do you think this model MONITOR MRM-5321 is compatible on the 500 EFI

If you have this mounting pattern, how much room is needed on the front ?



On my Baja, it's very short !!

**Watching as I want to do the same on my stock 502 EFI with CMI e-Top exhaust

Hello

Still without a solution ...

Seen in a offer in Croatia, a twin engine Mercury 500 EFI with closed cooling...



Not very pretty, but it is equiped

Yes. Did it on mine back in 2004-2005. Mounted the reservoirs in the gunnels, and painted them to match the engines. Worked perfectly. Use distilled water. Sorry... no pics! Boat literally sold within days after putting it back together.

Hello

Without aftermarket solution !!

I throught to install the parts of a 525 EFI on my 500 EFI,

but I just noticed that the heads do not have the passage of water at the exit of the heat exchanger crossover manifold !!!

Damage, that would have been simpler

Bye