Digital Water/Engine temp Gauge....

[Stumpknocker]

on a 305 Mercruiser Alpha One. How high should the operating temps be for this engine. It reads 170 or so on the hose. Does this sound about right?

 

[tommays]

Re: Digital Water/Engine temp Gauge....

fresh or raw water cooled<br /><br /><br />tommays

 

[Stumpknocker]

Re: Digital Water/Engine temp Gauge....

We dumped it in a lake this evening, to get it off the hose. The temps had been spiking up to 240 on the hose and jumped right back to 230-240 after just a couple of minutes in the lake. I'm not sure what you mean about fresh water cooled except to enquire if it uses outside water. It does. We think that either the thermostat is stuck or we put the lower unit on in such a way as to prevent the water coupler from installing properly. <br /><br />This mess was precipitated by ingesting weeds in a lake Toho near Orlando. It overheated and got pretty hot for a few minutes and the boat idled back to the dock. At idle it seemed to drop to about 180. Any throttle resulted in 230 up. We put in a new impeller, although the original looked quite good except for a small amount of "set" to it. The coupling tube that connects the water pump assembly to the upper unit was melted down pretty badly. Replaced that as well.

 

[Stumpknocker]

Re: Digital Water/Engine temp Gauge....

After a quick Google on cooling systems, I now realize I have no idea which system this 5.0 L carbed engine has. No paperwork with it. Joe bought it used. Is there any easy way to tell?

 

[Stumpknocker]

Re: Digital Water/Engine temp Gauge....

Anyone?

 

[tommays]

Re: Digital Water/Engine temp Gauge....

well is sounds raw water cooled you would have a heat exchanger with a cap like a car if it was freash water cooled<br /><br />its WAY TO HOT no matter what 180 would be a MAX temp<br /><br />the most likely thing would be your raw water pump but you say you put in a new one<br /><br />so the next thing is that something is cloging the water supply to the motor <br /><br />you can remove the hose from the drive were it hooks up to the motor and run it for about 15 seconds if you dont get a nice flow of water thats were to look<br /><br />you dont mention the stat but i have had stuff flow through and clog it <br /><br /><br />tommays

 

[Stumpknocker]

Re: Digital Water/Engine temp Gauge....

Thanks tommays. We bought a new thermostat just in case. Will probably put it in tomorrow just to eliminate that possiblity. We thought maybe we sucked up some weeds or Hydrilla (sic). Will try and remove the hose you mentioned. I'm more outboard oriented and Joe has little boat experience at all. So this cooling system is sort of Greek to me. When I first cranked it up on the hose after putting in a new impellor there was more water flowing out of the drive assembly from the engine. Now theres hardly any coming out there or even the prop. In the lake it didn't make any difference either. So we shut it down to avoid any more problems. Probably a clog somewhere.