Re: Flushing procedures for 40hp 4-stoke EFI
Hi Don,
I have a 2004 F60 EFI, which might be similar. Merc say you MUST flush every time after saltwater use, so I do so for warranty purposes, by backflushing through the telltale (pee) tube, which has a thread for a garden hose connector around it. Used for three seasons, and seems OK.
This rig credited to Rob Lake, a wrench in Pembrokeshire UK - photos attached:
Submersible 12v caravan water pump, connected to garden hose with standard hose connector on other end. Extend power cable and connect standard 12v plug. Use standard threaded connector to fit Merc socket around the telltale outlet (orange in photo.). 20 litre/5 US gall container with spout large enough to take the submersible pump, full of fresh water. If you take this with you, it is also a fresh water supply in case of emergency. I had to install a 12v socket in my boat (with fuse protection!), and made a small spanner from polycarbonate sheet, as photo. You might need to fit a small rubber washer behind the Merc connector to stop/reduce leakage.
I tilt the engine fully, attach connector, connect up, run pump until water runs out of prop., then start motor, run at idle (prop. spins slowly, which is normal), and stop engine before fresh water runs out, about 3-5 minutes. This is not as long as Merc recommend, but I reckon it should be good enough. I will continue like this until the engine is well out of warranty.
I keep my boat on a saltwater mooring for 3-4 months a year.
Is this flushing necessary, or are Merc just covering their *****? I don't know, but we also have a 30 year old Merc 500 (45hp), which has had 22-23 seasons use on saltwater. It had to have an internal cover plate replaced after about 20 years, this corroded through, and it stripped down ok for repair, but no other cooling issues. This engine was never flushed whilst on the mooring, but we ran it in a tank of fresh water (with some detergent) for at least an hour at the end of each season.
I hope this helps
O-G
