the water inlet hose back side of the impeller housing is lower than the inlet thru the transom so the impeller housing the inlet and outlet water hose always has water in it. To test what I am saying --- pull your boat out of the water -- put ur drive all the down and then pull off the back side water hoses to the impeller housing -- watch how much water comes out. The housing is never dry unless one pulls hoses and drains the housing however.

Great question...long answer. I lease a storage building with well water. After a rain (which seems to be happening a lot here in North Carolina this year) the hose bib I will ruin clear water for a few seconds and then so pretty nasty clay mixed water for a few seconds. It's inconsistent...so I have been trying to figure out a way to see the water (maybe in a tub) before it goes into the engine/impeller.

PS_I love this forum! You guys really help a newbie.

I tried this once with an Alpha drive in a 110 gal plastic tub (normally used to water livestock). The exhaust made the water bubble excessively spilling over the sides (no thru transom exh). The water got really hot really quick since most of the heat from the hot exhaust/water re-entered the loop. If you have thru-transom exh it might work a little better.

A better option would be to build a sturdy stand to elevate your water barrel then let the water gravity feed into the muffs (or however you get water to the pump).

Feeding from a clean water source is a great idea

dont know that I would worry about it. the water in the lake or river is probably dirtier than what the well is putting out. if it passed through the well pump it will pass the impeller and engine with ease. you would be amazed at the crap you are running through it at the lake.

At the shop I use to have a propshaft dyno and a big water tub like what horses drink out of on a farm.. We would slightly open the drain at the bottom of the tub and run a water hose in the tub for all engine running. Especially for 130 hp outboards and down. . Had a removable outboard mount on one side of the tub as well. The tub was great for older Volvos the ones that would dry crack the water hose to test that end of it.

I have the hose attachment that feeds both sides of the lower unit and I turn the hose on full blast and I've still toasted an impellor. Even idling I don't get 1/4 the water out of my exhaust using the hose that I get sitting in the lake. I have a 3/4hp well pump in an artesian spring that pumps twice the water I get from the hose at my home that has city water. Just saying my experience hasn't been good on the hose. Of course I'm only 2 miles from the harbor, so no big deal to drop it in for testing.

I never said you could rev engine on the hose/barrrl. I said the hose would supply the same amount of water feeding in a barrel or on the muffs. I would never tun it above idle on the hose.