Low water pressure

[sreill]

Some of you may know that Ive been having an over heat/low pressure problem. So far ive cleaned out the heat exchanger, changed the impeller.

I gave up on the do it yourself thing and handed the boat over to my mechanic.

He thinks that the thru hull hose at the transom that passes the water from the drive to the pump my have collapsed due to salt buildup.

He wants to block off that water supply completely with a plate and install a "south bay" sea strainer in my hull as my water supply. Any opinions on this? Anyone ever try this fix?

He says it will eliminate the problem of eel grass and it will actually feed more volume into the system

 

[Obsession]

GO FOR IT ! ! ! I can't recommend it enough on the Bravo 3
Did mine with Vetus clear strainer & clear hose. I didnt use blanking plate but cut inlet hose where it runs at side of engine & capped it off - found it much easier, No longer have overheating problem & can see water gushing into engine !:thumbsup:

 

[Zklink5150]

Have you tried the test to see if your pumping enough water? I'm not sure about your b111 but used this formula to test my alpha. Disconnect water input from
engine, get a 5gallon bucket, point hose into bucket, 1000rpms at 15 seconds should produce 4qts h20. I had 2 qts of h20 come out and found my thru hull hose full of impellar parts as well as slot of other unrecognizable nonsense. Just a thought before your change over.

 

[sreill]

I didnt try that. Seems like a good test though. Its out of my hands now and inthe hands of my mechanic.

 

[Ididntdoit]

I was having the same problem - instead of "repairing" the hose I converted the system and it works great make sure you use large enough "full Flow" strainers/ball valves/ fittings etc and reinforced hose rated for use under the water line Also make sure to cut and remove a piece of the drive hose (be careful of the bellows) - if you leave it deadheaded the drive will not get the flow through cooling it needs

 

[sreill]

Also make sure to cut and remove a piece of the drive hose (be careful of the bellows) - if you leave it deadheaded the drive will not get the flow through cooling it needs

The mechanic cut the hose inside the bilge and capped it off. No good?

 

[keokie]

BIII's are cooled in part by the flow thru of cooling water to the engine. I wouldn't eliminate that as the intended cooling is marginal at best.

Also, flow problems with BIII's can be a result of the passage thru the transom being collapsed, or the pumps sucking air do to the end plates being worn. Worn end plates are common on the 496 pumps (this can be remedied). The alternate water pick up can alleviate this for a bit, but as the pump wears farther it will fail again.

 

[sreill]

I would think that the drive being submerged in water would be enough cooling.

 

[sreill]

Also, flow problems with BIII's can be a result of the passage thru the transom being collapsed, or the pumps sucking air do to the end plates being worn. Worn end plates are common on the 496 pumps

There are different water pumps on the 496. The end plates you are referring to are on the plastic ones. I have the brass version of the pump that doesnt have end plates

 

[Ididntdoit]

I would think that the drive being submerged in water would be enough cooling.

The upper gear case is not submerged when you are on plane - the "directions" that come with the block off kits specifically address cutting the hose for this reason - I was told even if you have a drive shower you should still cut the hose

 

[Ididntdoit]

There are different water pumps on the 496. The end plates you are referring to are on the plastic ones. I have the brass version of the pump that doesnt have end plates

Just had my brass plates off and they are heavily scored - you can buy just the plate if the rest of the pump is good - I'm thinking about trying to have mine surfaced over the winter

 

[matthewmiller01]

I know it is a long shot, but do you have a pic showing where the hose comes through the transom? Is it accessible - or even able to be seen - from the engine compartment? I currently have differing pressures P to S. I've swapped the sensors and it stays with the engine, not the sensor. I have new impellers. I didn't see any scoring when I changed them, but didn't specifically check for it, so I can't say 100% that there was none. The water pressure is low on STBD. The hot water tank is off of PORT. I also had the out drive off last winter on STBD (only) for trim sender replacement, but the pressure difference was there before and after this. Thanks.