496 HO Drain Actuator
 

I have a leaking starboard drain actuator when I run WOT. This is part number 863716A2 which is no longer available according to Bam Marine and several other sites. Is there a new replacement part number or a rebuild kit? What are my options if this is no longer available?

Thanks.

Call Marc @ BAM, they will give you the best option. There are rebuild kits. Your spring is worn out, and allowing the water pressure at high speed to push through to drain.

You can also just remove the whole actuator from the system, and replace it with a length of pipe. Given that you live in Maine, you need to do a full winterization with antifreeze anyhow. As such, not a big deal. I bought my 496 equipped boat from Phoenix, and of course winterization was not needed. It had an actuator go bad early, and the original owner replaced it with the length of pipe. IIRC, it needs a 1.25" OD pipe section, about 6" long.

Have looked at the different serial number ranges and it appears the part is NLA because they now sell it only as an entire assembly (pump and drain), starting with 0W060000 and up. Looking at the raw water pump only and the drain system they both list only one part 8M0137218. This one replaced 862914T05

$840 each

I just get rid of them cause the leak at high rpms anyways. I have the adaption made with a drain plug installed. So simple 2 drain drain plugs does the exact as the air actuator draining water. End of story

Are there two different drain systems? My actuator is actually "built in" to the back of the water pump housing. So, I'm not sure how I would bypass actuator if I wanted to.

Also, can they get stuck closed as well as open? One of mine does not open when air pressure is applied.

There are two versions, one is seperate from the water pump and the other is part of the water pump. Mine is seperate.

Do you have any details on how you made these? How did you set up the drain plug fitting?

Pics please! I've had some unexplained water in my bilge, and I'm pretty sure they are leaking too, like the ones on my last 496HO boat were.

:worthless_without_p

Agree,
and Take the new design and replace with old design, all the water will drain out, no pressure required.

they are splice kits with a drain plug in the splice adapter. Came up with those many years ago. Since this thread I am sold out now. More to be made soon. You can drain these by the drain plug or just the pull hose off the back end whatever is easier .

There will 2 versions made inwhich I have a good idea to add something to the splice adapter.

There is guy up here a couple of years ago or maybe longer than that --- posted he had a 496 with a unfound leak for years, He called me and I told him about where the leak was coming from and I had the inexpensive fix. I think he replied a thx to me and it fixed his unfound leak. It was from the drain actuators.

How I found these leaks around mid 2000 s was I put a camera video in the engine compartment with lites and went to the lake. What I found was alot of the actuators drains leaked at high rpms for a short jist. Some leaked more than others but for the most part many did leak. At that timeframe there was about 200 - 496 s coming thru my shop per year. Many were not that familiar with 496s nor the scanning of them.

back then the main issues were IAC failures, foul spark plugs, water pressure alarms, some blown up 496 s, scared impeller housings, exhaust temp alarms, engine overheats some boost fuel pump failures and so on. And for the record not many even heard of an IAC muffler.back then. When would tell customers and even some dealers that the IAC muffler needed changing they would laugh and say thats funny because they thought it was joke and something we made up. .

BUP - any idea when you will have more? Im currently trying to find the rebuild kit but not having any luck and the whole drain actuator is NLA.

Thanks.

There is a Tee fitting 861505 which was used to drain the water out of the line going thru the first Gen cool fuel. I took one of them and added it at the raw water pump output side to drain water. Could also use on intake side

https://www.ebay.com/itm/New-Mercury...-/271546920490

https://cimg2.ibsrv.net/gimg/www.off...e9551e728.jpeg