Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Mercury 60 hp water pump

Posted by randolphp on 11/08/14 - 6:47 AM
#1

This engine - a 2007 Mercury 60 hp Big Foot - was winterized a year ago and not started again until today, Nov. 8, 2014. I attached a garden hose to the rear fitting (page 71 in manual) so water was flowing into the engine. Water was flowing out of the primary cooling water intake (page 36) at a normal rate. I started the engine but no water came out of the water pump indicator hole so I turned off the engine.

The engine has been used around 20 hours or less by a former owner who had routine maintenance done by an outboard motor mechanic at a marina.

Why isn't water coming out of the water pump indicator hole? Is the water pump broken. Should I have placed earmuffs over the primary water intake at the base of the motor? Why was water flowing out of the primary water intake and not the water pump indicator hole?

Posted by surfmonkey on 11/08/14 - 7:20 AM
#2

I've had similar issues with a 2003 90 hp Mercury four-stroke when first started at the beginning of several boating seasons. I started the engine using earmuffs but was getting no water coming from the tell tale hole. It turns out that the water pump was working fine but there was some debris blocking the water line for the tell tale. My guess is that it is the result of some corrosion breaking free from the cooling passages from being run in brackish water. Try running a piece of wire into the hole to break up the blockage. I've also noticed that if I run the engine with lower unit submerged in a tank of water or at the boat ramp the blockage will often free itself with the added water pressure from having the lower unit submerged and by increasing the engine rpm's at idle.

Posted by randolphp on 11/09/14 - 3:21 AM
#3

Might the water pump be working even if there's no water coming out of the indicator hole or is it too risky to assume that? The engine has not been used much so I'd think that the impeller in the water pump would be in good shape. Do you think that there might be water circulating through the engine even though there's no water coming out of the indicator hole? Is it possible that the water pump might be "sticking" and not revolving like it should? I'm inclined not to think so but my knowledge of and experience with outboard motors is limited.

Posted by wing15601 on 11/09/14 - 6:01 AM
#4

The impellers on modern marine engines begin to age as soon as they are installed as they begin the process of hardening and they lose the initial flexibility. You don't say how long it's been since your impeller was changed and it is a cheap easy maintenance item that will save your engine. Get a repair manual for your engine. Hardly any mechanical ability is requires to change the impeller. That being said, the water pressure may not have been sufficient when you ran the engine. If it were my engine I would change the impeller before running it again.

Edited by wing15601 on 11/09/14 - 6:04 AM

Posted by surfmonkey on 11/09/14 - 7:35 AM
#5

With the 90 hp model I removed the engine cover and was able to feel water pressure and an increase in temperature in the hose that ran from the engine block to the tell tale hole. That was how I determined that there was a blockage in the hose rather than a bad water pump. The 90 hp engine is also supposed to alarm when overheating so it made me feel a little bit better about running it while I attempted to clear the blockage.

Posted by gchuba on 11/09/14 - 8:23 AM
#6

I would suggest contacting the boat mechanic used by the former owner or a mechanic familiar with your motor (you will be developing a relationship with a boat tech at some point anyway)before tearing it down or poking with wire (both which may very well work). I had a 1981 Johnson 235hp outboard that had a trickle of water (looked like peeing) coming out of a release hole. All the "home garage" mechanics on my boat said I had blockage and it should be streaming/pouring out. Talked with "Lockemans" (old Detroit boat shop) and was told working as it should. A thermostat opens for pressure relief. Saved some effort by not taking it apart or damage by poking. I also "bit the bullet" with a 9.9hp Yamaha kicker motor I purchased used. I had it professionally serviced and I now can do the maintenance (impeller replace, etc...) knowing the internals were done and professionally looked at.

Garris

Posted by randolphp on 11/17/14 - 2:40 PM
#7

I'm replacing the impeller. Have the lower unit off. It came off pretty easily. Have studied a couple You Tube videos about replacing an impeller in a 60 hp Mercury and I'm finding them very helpful. It will be interesting to see how aged the impeller is. It's the original impeller; engine built in 2006 or 7 and not used more than 20 hours total.