50 hp over heating

[hamburgerman]

88 50 hp force HELP! I had over heating after 5 min on lake and motor died. Wouldn't restart till later at home. I checked heads, flushed system, put in new impeller and thermostat changed head gasket and tested at home in a barrell, works great. Ran it as book said then retorked bolts. Still ran great at home. Took it to the lake today, ran about 15 minutes and over heated. System is free and clear of blockage. When at home blows water out of pipe plug on top of motor great. What could it be?

 

[roscoe]

Re: 50 hp over heating

Good question.<br /><br />Welcome to iboats.<br /><br />You don't have it trimmed out too far that the water intakes are out of the water, do you?<br /><br />Sounds like you did a good job, got me stumped.

 

[hamburgerman]

Re: 50 hp over heating

Is a manual tilt trim so don't think thats it. I have checked and the cavitation is correct for the boat. It does show a bit of water spitting at all times so I know something is getting in there. Could it be that the impeller housing could be worn out? It does show some signs of wear. Could the water tube seal, or the disk seal go out? Could these be causing it? I am going to replace the impeller and its housing to see, as these aren't real expensive. If that doesn't work. I just don't know.

 

[eurolarva]

Re: 50 hp over heating

Correct orientation of the fins on the impeller are a must. Place the impeller on the drive shaft with the impeller key. Lower the water pump down to the impeller. Push down hard on the water pump while slowly turning the driveshaft clockwise till the impeller seats in the water pump. If impeller fins are inverted it will restrict the amount of water flow. Back flush through the Thermostat opening. If problem continues try running one time out without the Thermostat and see if it helps or not.

 

[hamburgerman]

Re: 50 hp over heating

I replaced the impeller housing and all new seals pumps great! I let it run 15 min.and it has never pumped water like that I am going out to lake test today see how it doeson the water.

 

[roscoe]

Re: 50 hp over heating

Good deal, good job, good luck.

 

[hamburgerman]

Re: 50 hp over heating

apparently my problem wes the seals in the water pump housing. that caused poor water pump performance ( no warning horn) then the over heat caused the head gasket to leak compression into the water jacket and push out any water that tried to make it up there. Anyway I re-torqued and problem fixed thank God