I know some 496 owners are experiencing problems circulating water in the engine while the boat sits on the trailer. A mechanic told me that 496 cooling circuit design is not ear muff friendly and may need some sort of a pump to force water in the drive… Things seems worst when the block as been pressurized with the hand pump. In May, I had to get the boat at a ramp in the water so I can finally see water out from the exhaust!

What’s the trick?

I haven't had any trouble running mine on the hose. I use the merc muffs that have the rod that goes through the water passage to the other side. Maybe you don't have enough water pressure at your house?

Do you have a Bravo1x with the low water pickups? I do and I use the muffs but I need to put a piece of duct tape over the low water pickups on the front of the bullet to make sure the pump gets as much water as possible. Just don't foget to take the tape back off when your done! But I'll admit that I think it's still has marginal water pressure.

No problems here either....except one time I got distracted and forgot to turn the hose on.

Try duct taping the low water pickups on the bullet. Probably necessary if you don't have good water pressure. I use the Merc muffs too. I also rev up to 1500 which really helps get the water flowing.

I think We have a clue here... : "merc muffs that have the rod that goes through the water passage to the other side"

My muffs are generic and have no rod. My setup is probably not tight enough around the water passage. I'l try those. Yes, I have always taped my low water pickup.

Thanks guys.

LOL! I did the same thing once. I'm standing there saying why the phuck isn't any water coming out the tips? OH NO!

If You Pumped Up The Block The Pump Will Not Pump ! Cant Get Any Vacum To Pull The Water

Stating you have to get the boat back at the ramp once it has been air pumped?

I'd just pulled off the water pump assembly and the feeder hose, and made my own t-fittings for a fresh water flush kit to the directly to the garden hose. I hate using muffs with a passion. It was a ***** to do, especially on a twin engine setup, but totally worth it in the long run.

When I did use muffs though, I just had the generic ones from Boater's World, rectagular on each side of the upper water pickups, tape off the LWP. Make sure you rotate them (with a little bit of WD40 to lube it) so the rectangular muff is verticle in line with your verticle upper water pickups. You may also want to Y two garden hoses together toward your outdrive to provide more pressure to your drive.