270 Outdrive Seawater intake leaking

[ebne0018]

I have a '83 270 outdrive paired with an aq125A that isn't pulling in fresh seawater (when hooked up to a hose. I haven't tried in the water yet). I replaced the impeller but the new impeller didn't fix the issue. I wanted to see if there was a blockage in the outdrive so I removed the short piece of flexible host in the engine bay and ran some water through it. Water came out of the seawater intake on the outdrive but it also leaked out near the top of the outdrive.

This is my first I/O so I don't have much experiance with them yet.

Is it correct that the impeller creates a vacuum to pull in the fresh seawater and this leak would break this vacuum making it unable to pull in water from the intake at the bottom of the outdrive?

How difficult is it going to be to change this part? It appears to be part 11 on the diagram.

Thanks

 

[Maclin]

Yes, the raw water pump on the engine draws water up through the drive.

Couple of things to be aware of...

There is a drain hole on the very bottom of the drive that must be plugged before running it on the muffs. If this is left open the pump can lose suction.

On the drive intermediate housing there is a hose fitting that can deteriorate, and the pump loses suction there. That is about where you describe where you see the leak. This fitting is readily accessible when the upper unit is removed, which is how the drive bellows are serviced. This area is underwater when sitting, and water is available for cooling at lower speeds, Once on plane this area Is exposed and if it is compromised the engine will overheat.

Next thing is the inside plumbing fittings on that drive between the lower unit and intermediate unit can sometimes introduce a leak.

 

[Maclin]

I looked at the pic closer, I think you may need to look at the connections inside the drive if the water is running out where the arrow points, part #11 in the drawing probably. The fitting I described, part #28, is on the next plate above that and looks pretty new form that angle. The gasket for the fitting is flat and is only to seal the fitting to the housing. The part that is failing on yours is inside the drive.

 

[ebne0018]

I checked the fitting when running water through it and it was bone dry. The water is definitely coming from below the fitting. I found repair kit that isn't that expensive: https://www.boatpartheadquarters.co...WhgAIhMLPoUQUGDXcLRq7AuKxMrkOsmRoCbsoQAvD_BwE

Looking at the 270 service manual it looks like I have to remove the the whole unit and then press out parts of the steering system. Any idea how hard of job this is?

 

[Scott Danforth]

you have to split the unit and the shaft comes out, however that is most likely not it.

make sure your raw water inlet casting did not corrode and fail. it is prone to failure in fresh water and salt water and should be replaced every 2-3 years along with your bellows. this is the casting shown in your over-priced "kit"

this casting sits on top the hollow swivel pin. held in with two small screws

pull your drive and look at the casting.

if you havent pulled your drive to replace the bellows in the past few years, may as well do that now too. inspect your PDS while you are in there.

 

[ebne0018]

The casting was the first thing I checked. The leak is definitely coming from below the casting.

 

[Scott Danforth]

The rubber gasket under the casting seals to top of the swivel tube. If its leaking below the tube has either failed, or the gasket under the casting is leaking. Pull the casting, i bet your gasket is cut

 

[kenny nunez]

There is a “O” ring just below the suspension fork at the very front of the lower gearcase that may be where the leak is. When the boat is on plane it will allow air to enter the incoming water.

 

[dennis461]

Yes, that connection is hard to get to, but I suspect you already knew that.
If it won't work on muffs, it won]'t work on the water.