How often do you change your intake impeller?

LouC · **Posted:** Wed Jul 01, 2015 4:58 pm

rpengr wrote:

LouC wrote:

...Last fall they dredged the harbor and now its 6-7 feet deep at low tide which is great. 13-15 feet deep at high tide. Best I ever had.

I found it interesting how high your tide is compared to South-East Florida. Our tidal change is 3.5 ft at full moon. I was guessing it is the shape of Long Island Sound that does it.
I looked up this website about the topic: http://oceanservice.noaa.gov/education/kits/tides/tides08_othereffects.html

Quote:

The shape of bays and estuaries also can magnify the intensity of tides. Funnel-shaped bays in particular can dramatically alter tidal magnitude. The Bay of Fundy in Nova Scotia is the classic example of this effect, and has the highest tides in the world—over 15 meters.

Wow. That's about a 50 ft Tidal Change in the Bay of Fundy Nova Scotia :shock:

The natural tidal change without shoreline influence, or wind, is about 3 ft. (such as seen by remote islands)

Sorry...off topic, but interesting.

Ray

Yes it is, even regionally there are differences, we on the North Shore of LI have an average 6-7 feet change, but the South Shore of LI has just a few feet. What that affects is the kind of trailers people use. On the South Shore there are more bunk trailers, up here there are more roller trailers. A bunk would be difficult to use at low tide at most of the smaller ramps around here. So I have a roller trailer and a long tongue to keep the rear wheels of the Jeeps out of the salt water....

GottWhat · **Posted:** Wed Jul 01, 2015 5:17 pm

I believe most manufacturers recommend impeller replacement every 2 years.

Toddely · **Posted:** Thu Jul 02, 2015 10:03 am

rpengr wrote:

Toddely wrote:

Ray, Naples Florida.. My inlaws live there, we're there a few times a year. If you get over there go into the Naples dock area, very nice canal and homes in there, you can dock a the naples dock and go have lunch at the Dock. its a great place for beer and lunch or dinner.. We load up on the middle neck raw oysters.. Tasty , Tasty. There are a couple huge yachts that dock right there . ya cant miss it.. You can actually go farther down and visit "Tin City" its like a hut full of shopping and a couple bars also. Were looking to move over to this area in the next few years.

Next time your going to be down there, feel free to send me a PM. Maybe I'll be able to bring the boat over. It's about a a 3.5 hour trip on the trailer for me.

Ray, Were heading back down sometime in the middle or end of Sept. We love the waters down there, clean, alots of sea life, Dolphins.. Manatees . The norm.. We try and get out as much as we can when were down there. I will keep you posted.

RichA · **Joined:** Wed Jun 25, 2014 12:37 pm **Posts:** 98

LouC wrote:

OK here's another tip if you want your impeller to last. When you first start it up after winter storage, the hose from the lower unit to the impeller housing is dry inside (unless you fill it with -100 AF like I do when winterizing). So the impeller runs dry till the water gets up there from the lower unit, which is a fair distance up hill. This affects Volvos and Bravos mostly, Alphas and Cobras have the pump in the lower unit pushing the water forward
So I do this (even tho I have a Cobra and fill the hose with AF):
Put the muffs on the lower unit. Disconnect the hose that comes up from the transom to the impeller housing. Fill that will water, then re-connect the hose. The muffs will keep it from leaking out. Then turn on the water hose. This will prime your impeller like in a second and reduces wear from dry starts.

It seems like this would only be an issue if your first start is with the boat in the water. If you're running on muffs, won't the pressure from the hose fill the system before you start (noting the water pouring out after I hook up the hose and before I start)?

LouC · **Posted:** Thu Aug 20, 2015 1:03 pm

Not as much as you would think; with the Volvo and Bravo style impellers that water has to travel up hill about a foot and a half and then forward by about 4 feet. When I do a Cobra impeller which is at the rear end of the upper gear housing I test water flow both ways. With the impeller housing off, I hook up the muffs and turn on the hose. To get water to spurt out of the impeller housing which is only about a foot above the water intakes I have to hold the muffs tight to the lower unit.
Then I disconnect the raw water intake hose at the Thermo housing and stick a garden hose in it and turn on the water. This tells me that everything is clear both ways.

When the boat is in the water hydrostatic pressure fills that hose. However I've teplaced thermostats with the boat in the water and had to remove the raw water intake hose at the thermo housing. Water does not just spurt out unles you lower the hose below the water line level. I always put a wood plug in to all the same.

www.iFourWinns.com

How often do you change your intake impeller?

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