93 evinrude 25HPOver Heating

[Kapt Bobby]

I have replaced the Impeller twice in a few days thinking it was bad. When I start the Motor it runs fine, water shooting out of the tell tail and all of that .then about 15 mins later no water coming out of tell tail or anywhere else,and the motor runs rough . Any ideas of what is going on and how i can fix it???

 

[tphoyt]

Could be some blockage somewhere. Were they any missing pieces of the first impeller you changed? Check the thermostat as well to be sure it’s not stuck closed.

 

[jimmbo]

Are you running the Motor on Muffs, in a Tank, or on the Boat in the water?
If on Muffs, you would be able to see all the Places that water will exit the Motor, not just the Teletale(I really don't put much Faith in them, as they just indicate water makes it to the Powerhead, and little Else)
What Speed is this Happening at, Idle, Cruise, WOT?
What do the Plugs look like? Signs of water/Very Clean?
What Else was replaced when you did the Impellers?

 

[Kapt Bobby]

I have the motor in a tank . I bring it down from a half throttle to an Idle . T motor runs really nice until it gets hot after about 15 mins.Nothing was replaced but a new Dirhard battery.

 

[jimmbo]

So it is Pumping water at 1/2 Throttle(in tank, in neutral) and quits when you slow down? Is that 15 minutes total run time, or after it slows down?
Can you put your hand on the Top of the motor, or Cylinder Head?
Does the Paint on the Head/top of Block, look burnt?
Has the Head ever been off the Motor?

 

[flyingscott]

Is the key in the impeller?

 

[saltchuckmatt]

You might need the whole pump kit. What did your wear plate look like?

 

[Kapt Bobby]

Key is in and it is the whole pump kit

 

[saltchuckmatt]

Well your getting a good stream and then your not...that's an odd one.

Usually, good stream but still gets hot. We deal with that one all the time.

Tims original q....was there missing pieces to your impeller when you first examined the water pump?