Running outboard without lower unit?

wmk0002 · Jan 15, 2018

Can an adapter to be made to safely adapt a garden hose to the copper water inlet tube of an outboard? If so is there an ideal psi to run the supplied water at? I would think a reducer with a pressure regulator and a clamp fitting would be sufficient.

There is an outboard for sale locally which has a busted lower unit as a result of freezing. It is a good deal if I can just get the compression and spark to check out ok when I go look at it but I would like to be able to run it at some point before deciding to part it out myself or to repair or replace the lower unit.

CedarRiverScooter · Jan 15, 2018

You can run it for a minute without water. The impeller might get burnt but in this scenario you probably would be replacing that anyway.

Edit - if you are going to drop the LU to start it, then impeller comes off with that.

LDUBS · Jan 16, 2018

Just out of curiosity, why can't you leave the broken lower unit on when you start it? Is it frozen in gear or something?

wmk0002 · Jan 17, 2018

LDUBS said:
Just out of curiosity, why can't you leave the broken lower unit on when you start it? Is it frozen in gear or something?

It is not, but it may still be salvageable even if just for parts so I wouldn't want to get any more water in there than necessary.

wmk0002 · Jan 17, 2018

CedarRiverScooter said:
You can run it for a minute without water. The impeller might get burnt but in this scenario you probably would be replacing that anyway.

Edit - if you are going to drop the LU to start it, then impeller comes off with that.

I'm not opposed to starting it without water especially if there is no impeller present to burn up. However, I'm still curious if one can be ran for continued period of time on a hose directly to the water tube. It could be beneficial later on down the road for other outboards. I recently bought a new house which came with a 40 x 60 insulated shop so I plan to get more into outboard repair as a hobby.

crazymanme2 · Jan 17, 2018

Yes you can run it without lower on with water hooked up to it, done it before. Don't turn water on all the way,remember the size of the copper tube compared to your hose.

timsmcm · Jan 17, 2018

Yes I have clear plastic hose that slides over the copper tube and gets tighten down with a small hose clamp. On the other end I have a hose end with a barb the same size as the plastic hose. Works well for running the motor with no lower unit. It also works well for checking to see if the water tube gromets look like little buttholes. Sorry couldn't help my self but that is what they look like.