overheating at trolling speed

[Edstrom]

1978 Merc 175 h.p. outboard. Water dribbles from the peehole. It overheats at trolling speed but runs great at top speed. Does the upper impeller need to be replaced? Also is there a fresh water flush on this engine?

 

[Scottj25]

Re: overheating at trolling speed

You might want to check out getting larger pickups for the water have you checked your lower unit. As far as I know there is no upper water pump, and you need to remember your engin was never ment to run at trolling speed for a long time.

 

[Spidybot]

Re: overheating at trolling speed

You almost said it yourself. It doesn't work while idling for longer periods. Either the motor just isn't made for it or your impeller needs replacement.<br /><br />BTW: Why not add a nice little 4-stroke for trolling? Would save $$$$s on gas and at the same time provide the backup security.

 

[clanton]

Re: overheating at trolling speed

Check waterpump, thermostats, pressure relief valve.Is overheat alarm buzzing?