Fried the 4th impeller kit? (OMC 2.3)

[Bottomsupscott]

Ok this latest install (4th in as many months) tested the water hose up to thermostate housing. Water flower. New thermostat but now I am wondering if it is not working? So do I need to split upper drive from lower and inspect water tube or???
Please....I am about to scrap her...

 

[hugh g]

Ok this latest install (4th in as many months) tested the water hose up to thermostate housing. Water flower. New thermostat but now I am wondering if it is not working? So do I need to split upper drive from lower and inspect water tube or???
Please....I am about to scrap her...

Hook up the muffs, turn water on. Without starting engine you should see a pee stream from the vent on the impeller housing. If not ypu may have a blockage. Did the impellers that fried come out in one piece or in pieces? If they were in pieces you may have a blockage.

 

[Lou C]

I think I explained how to check for blockage in the lower unit water passages & the water tube gaskets but if not:
1) remove impeller housing
2) hook up muffs and turn on water
Water should spurt out of one of the openings in the impeller housing. If not, hold the muffs tight to the lower unit; if you get water then your muffs aren’t sealing right and you need better ones, if still no water then yeah it’s time to split the drive. A couple of bad overheats can melt the lower water tube gasket. And they go bad just from age. You should also back flush the water intake hose from the thermostat housing and water should come out of the other opening in the impeller mount.
Are you using OE impellers and housing? Not Ch!na junk from Amazon or eBay please

 

[Bottomsupscott]

Well, I will go through it all again, purchase and install new OE kit. I will report back as soon as I learn anything.
Thank you Gentleman!

 

[hugh g]

I need to change my response. You won't get a pee stream from the impeller housing unless the engine is running. Sorry bout that!

 

[Lou C]

Correct forgot to mention that.

 

[Bottomsupscott]

No, I gotcha', thanks gentlemen!

 

[KM7]

I had a similar problem, melted an impeller due to it running dry. The cheap plastic hose adapter (muffs) did not squeeze hard enough to seal well and get the water up to the impeller. I switched to metal muffs and everything is fine now.

 

[Ferson206]

I had some impeller issues this past year, ended up getting a big tub from home depot that, when full, just covers the intake holes, so I could really be sure the impeller had access to water. Then followed hose from transom to thermostat housing, and detached that end to see if water was actually getting from impeller into the boat. I ended up having some grease blockage in the sterndrive itself, as well as small blockages in my heat exchanger. Once blockages were cleared, that hose coming up through transom went from dry to gushing, then I could move to next step in cooling system.

 

[Lou C]

Ok you will have better luck with better fitting muffs than running it in a tub. The best fitting muffs I have found are the round Merc/Quicksilver ones with the metal rod/clamp that goes through the water intake holes. You will have to drill an 1/8” hole in the plastic water screen to use these but they are the best I have tried them all…

 

[hugh g]

The rubber cups can also wear out & deform which can reduce water flow to the drive. Best bet is to spend a few bucks more on a good pair & stay away from the junk sold at Wally World & ebay.

 

[Lou C]

I used to use the Tempo rectangular muffs and what I found was that the rubber tends to be too stiff to conform to the lower unit. The Merc/Quicksilver ones are much softer rubber.

 

[Bottomsupscott]

You guys are awesome...thanks again...

 

[Bottomsupscott]

I used to use the Tempo rectangular muffs and what I found was that the rubber tends to be too stiff to conform to the lower unit. The Merc/Quicksilver ones are much softer rubber.

The round ones that actually stick on through a slight vacume or suction?

 

[KM7]

There is no "suction". Water is coming out of your hose under pressure. It goes into the hose adapter/ motor flush (muffs) and into the bottom of your outdrive. The water has to travel up to where the impeller it. Maybe 2 ft. If the hose adapter does not make a good seal and squeeze the outdrive, all the water will just spray all over the outside of the outdrive. Not enough water gets up the the impeller and it spins while dry. That's the end of your impeller.

The key is to get enough water pressure and a good seal to get the water up to the impeller. The cheap plastic hose adapters don't seal well enough. You want an adapter with a metal bar holding the 2 sides. Like the picture. Some adapters have water coming in from both sides. That seem like a waste. It's going to the same place. An adapter with the hose on one side works fine.

The one pictured does have the rectangular muffs and they can be a bit stiff as Lou mentioned. If your OD is flat where the intake is, that should not matter.