First start after lower unit rebuild - new boat owner

[Chips0701]

I had my lower unit rebuilt last year and it was winterized at the same time. This spring was the first time it’s been started for a while. I’m a newer boat owner and I’m not sure if this is normal. I had the boat running for just under five minutes. A 10 second clip of the water and exhaust coming from the unit is attached.

 

[jimmbo]

Welcome to iboats

What is your concern?

 

[Chips0701]

Thank you for the welcome. Full disclosure this is year three of me owning it. Last year I didn’t get to run it because of the lower unit rebuild. The first year it was already water ready so it’s my first time starting it up in the spring. I was just concerned with the amount of exhaust coming out of locations other than the prop.

 

[jimmbo]

There are Idle Reliefs that are are part of the Transom Plate, that have a bit less backpressure than the path thru the Prop. Needed to be able to start the Engine, and allow it to Idle

 

[tpenfield]

Welcome to iBoats. . . .

Generally, you would start the engine with the outdrive an a lowered position. Not sure about the water, but see how things look with the outdrive in a lowered position.

 

[Chips0701]

Thank you. How long should I let it run at idle before I might see it clear up? I’ll start it up tomorrow with the trim lowered and see if there is a difference.

 

[jimmbo]

Clear up?

 

[Chips0701]

I won’t be able to run it again until tomorrow. Will let you know then.

 

[Horigan]

If you're referring to the smoke/steam, that is independent of the lower unit service. It's associated with the engine and it may clear up when the engine warms up.

The reason you shouldn't run the engine with the drive up is because it is very hard on the U-joints at the top of the drive. These spin even in neutral.

 

[Scott06]

Looks completely normal nothing to worry about. good water flow
yes lowering the outdrive is easier on u joints but at idle no issue in my opinion. For years my family has had a place in a shallow cove on a lake, water is shallow enough that outdrive has to be all the way up to get in the hoist. on my last boat u joints were changed after 23 years...

 

[Chips0701]

If you're referring to the smoke/steam, that is independent of the lower unit service. It's associated with the engine and it may clear up when the engine warms up.

The reason you shouldn't run the engine with the drive up is because it is very hard on the U-joints at the top of the drive. These spin even in neutral.

Thank you. Will be running it again tonight when I get off with the lower unit down!

 

[jimmbo]

Thank you. Will be running it again tonight when I get off with the lower unit down!

That statement, just doesn't sound right

 

[Chips0701]

You’re not wrong haha

 

[Lou C]

An OMC Cobra usually puts out more water under the transom mount, like this vid, I'd consider replacing the raw water impeller, a very easy job on those.
View attachment Cobra running on the water hose.MOV

 

[Chips0701]

An OMC Cobra usually puts out more water under the transom mount, like this vid, I'd consider replacing the raw water impeller, a very easy job on those.
View attachment 379340

I think that is just the product of the poor water pressure at my house. But I may be able to test on someone else’s supply.

 

[jimmbo]

How long of a Hose, and its internal diameter, as well as any fitting on it

 

[Lou C]

It is more a question of volume of water than pressure. Open cooling systems like these move a high volume of water to carry away the heat of combustion and the exhaust. The fact that your exhaust is steaming suggests low raw water flow, either from the hose or your impeller isn't pumping enough water. I have the same system and it never steams.

 

[Chips0701]

I have an old house with half inch or quarter inch supply lines throughout. The host itself is a standard garden hose with a 50’ run

 

[Chips0701]

I have an old house with half inch or quarter inch supply lines throughout. The host itself is a standard garden hose with a 50’ run

Put it this way, I can’t run a pressure washer off of the hose because it doesn’t supply enough water fast enough.

 

[Scott06]

Put it this way, I can’t run a pressure washer off of the hose because it doesn’t supply enough water fast enough.

put it in the water and let it supply water off the pump by itself before you worry about it. Your home is not enough