Getting warm on muffs?

[calincoltsdad]

I checked the impeller in my raw pump, everything looked ok, but I turned it around because I've read where you can actually put it in backwards. Dont know if thats true or not and it didnt look any different either way to tell the truth but I got alot more water flow after that. It took alot more time for the engine to get hot but still got up to 185. Can the engine get that hot just idling in a tub of water, water was staying cool. What about on muffs since you're forcing water into the engine then? Should it do ok in the lake since the boat will be moving and water forced due to motion? Just wanting to be sure before I go out again and try it?

 

[captmello]

Re: Getting warm on muffs?

Need to know what your working on.

 

[jerryjerry05]

Re: Getting warm on muffs?

I'm assuming it's a Mercruiser??? The muffs DO NOT force water into the motor.The impeller gets SET. If you turn it around you are forcing it to bend the other way and it can cause damage to the vanes.
The muffs are for temporary use.You shouldn't run the motor till it gets hot.The hose seems like it might have enough water but it doesn't.The lake/ocean has millions of gallons.The hose no where near that.
After you replace the impeller.When ever you have it in your hand replace it. If you run it in the water and it still gets hot then the risers are possibly clogging.J

 

[calincoltsdad]

Re: Getting warm on muffs?

Working on a 4.3L V6 Yamaha. I bought the boat a couple weeks ago and the previous owner said he had replaced the impeller. Someone had told me that some of them can be installed with the ends of the vanes pointed backwards so I turned the impeller around and got alot more water flow up to the engine. I had the outdrive in a tub of cold water and had the garden hose feeding cool water back into the tub while idling. Temp got up to 185 at idle but I had alot of water flowing from the exhaust under the boat and all 5 holes in the outdrive was discharging fully.

 

[jerryjerry05]

Re: Getting warm on muffs?

Boat used??? How old?Fill out the profile.
Like I said if you have the impeller out replace it.Put the boat in the water(no tubs,no hose)Then see how hot it gets.Don't change the direction of the impeller once it is in.
When you run it in a tub the unit will cool but not as good as in the water.J

 

[calincoltsdad]

Re: Getting warm on muffs?

Boat is used. Had it 3 weeks. Seller said he changed it right before selling. I pulled it out and looked brand new. been it the water only once. I pulled it to see if they could be put in backwards. Turned it over and got alot more flow from the raw pump. Does anybody know what webiste I can get a thermostat for this engine? It is different than the mercs due to having 3 seperate thermostat housing stacked on the intake. Every place I've called dont list one for the Yamaha make. Even West Marine shows no listing.