Flushing motor after salt water

[The Quadfather]

Can someone tell me what you believe is a fine amount of time to flush out my 25 hp Merc. after running it in salt water? I use the ear muff things over the intake, lots of good output coming out of course.
I have done it for like 3-4 minutes, but wasn't sure if it should go longer. ( I guess it's normal if the outflow water from the upper unit is warm, the lower unit puts out cold) I follow that with a good hosing off of everthing, prop, etc.
There must be a good reason, it is a brand new motor.

Thanks

[A9]

A few minutes is more then enough. Do that and hose off the whole engine and you will be good.

[jmay]

I would recommend just a couple of minuites after the exhaust water on your tell tail stream is warm. That indicates the engine is up to operating temp and has cycled out the old (salt) water left in the cooling system. Total process should be less that 10 minutes.

For added protection coat the powerhead with a light coat of silicone spray, it will keep the corrosion away (keep the spray away from hoses)

[Easy Limits]

I usually flush for five minutes. You do want to make sure you are not using full water pressure when flushing though.

[cavdad45]

Can someone tell me what you believe is a fine amount of time to flush out my 25 hp Merc. after running it in salt water? I use the ear muff things over the intake, lots of good output coming out of course.
I have done it for like 3-4 minutes, but wasn't sure if it should go longer. ( I guess it's normal if the outflow water from the upper unit is warm, the lower unit puts out cold) I follow that with a good hosing off of everthing, prop, etc.
There must be a good reason, it is a brand new motor.

Thanks

If you continue to do what you are doing you are doing fine. I agree to wait for the water on the tattle-tale to warm up because then it flushes everything as the thermostat is then opened up. Also the extra time will add life to the water pump impeller which being rubber would be the first component to fail.

[The Quadfather]

Thanks guys.

[Drewp]

I usually flush for five minutes. You do want to make sure you are not using full water pressure when flushing though.

Hey Easy Limits,

I have never heard of this before...what's the reasoning behind not using full pressure? Just curious.

[Easy Limits]

I don't know really. I guess full pressure could cause damage to the impeller inside the motor. My owners manual for my '05 Merc says not to use full water pressure.

[gpc]

I don't know really. I guess full pressure could cause damage to the impeller inside the motor. My owners manual for my '05 Merc says not to use full water pressure.

Easy limits, on your 05 Merc, is there a place to hook your hose right up to the motor when you want to flush it out? On my 01 Johnson there is, and 2 times a go I turned it on full blast and it just shut off. It still ran fine, but its never shut down out of nowhere before, this was probably the reason why.

[Easy Limits]

Yes, there is a place to hook a hose on to the motor. I don't use it any more though. The hose hookup has caused me nothing but grief. I flush from the bottom up with ear muffs.

[cavdad45]

Definitely use the ear muffs. By the way, if you don't use full pressure, make sure you are not using too little water because a water pump impeller could be the least of your problems. It sounds simple, but it would surprise you to see the things boat owners have done to new motors.

[gpc]

Yes, there is a place to hook a hose on to the motor. I don't use it any more though. The hose hookup has caused me nothing but grief. I flush from the bottom up with ear muffs.

Easy Limits, what do you mean by grief. The first time I used it we didnt get the plug back in all the way and it spit out water, but I tightened the plug and it worked fine. I only flush the engine a few times a year. I flush it after taking it out in the salt and when I winterize it. I am new to caring for a boats so any help is very appreciated.

Also what kind of ear muffs do you use? I have some for my 8 hp kicker, will those work for the big motor as well? Or do I have to get a bigger pair?

[cavdad45]

Tempo makes a good earmuff-type motor flusher that only runs about $7. We used these for more than 90% of our motors when I worked for the marine dealer. There were some newer 4-stroke Mercs that they would not work on because the intakes were under the cav plate like they are on nearly all of Mercury's kicker motors. Ask your local shop what they would recommend for your brand of motor, but most motors will take the earmuffs.

Outboard jets have a little screw in flusher, but once again the older units don't have that tapped in as well as some of the newset models.

[Easy Limits]

Easy Limits, what do you mean by grief.

When I would screw the hose in to the motor the hose inside the motor would get twisted up and then my motor wouldn't "pee" like it was suppose to. Then the motor would over heat.

I just use the normal muffs that you can buy at any store that hose boat stuff.

[cavdad45]

Easy Limits, what do you mean by grief.

When I would screw the hose in to the motor the hose inside the motor would get twisted up and then my motor wouldn't "pee" like it was suppose to. Then the motor would over heat.

I just use the normal muffs that you can buy at any store that hose boat stuff.

That flusher that you are talking about. It doesn't screw in directly the the motor block does it? There are some that do and those are NOT meant to be used while the motor is running. The ones that screw directly into the block bypass the water pump resulting in overheating, no tattletale water, and burned up water pump impellers and occassionally trashing water pump housings.

I hope that's not the kind you were talking about. Stick to the earmuffs when running the motor for flushing like you are doing.

[Easy Limits]

No, the flusher has a hose that runs between the inlet on the outside of the motor to somewhere around the motor head. That hose would get all twisted up when I would try to screw in a garden hose to the hose fitting on the outside of the motor.

[gpc]

Easy Limits, I know exactly what you are talking about. When I do it I have somebody else hold the hose a little bit back and kind of twist with me. Its almost impossible to get the hose as tight as it should be with only one person working the hose.

cavdad45, What would be considered the motor block? The connection to where you hook the hose up to my motor is right underneath the cover, in the back of the motor. You dont have to take the top off or anything, it just sits right below the lever to pop the top off. It wouldnt surprise me if I was doing something wrong.

[cavdad45]

GPC, If you take off the cowling and follow the hose back until it hits something. Some will go right into the powerhead while others will pump water down through the water pump just above the lower unit. I would call the dealer that sells your particular manufacture and talk to their service center, just to be sure.

With so many makes out there it's hard to make a generalized statement about where that hose fitting actually puts the water. A few years ago, we had a salesman telling his customers that you screw it in and fire the motor off. We had to deal with a few blown up or siezed motors and a pile of waterpumps until we found out where they got that info from. New motors with voided warranties, we took a bite on that one.

It is always safest to use a flusher that pumps water up from the lower unit. Like I said in other posts, the ear muff type is the best for most applications.

Call your dealer for specific info for your motor. Best advice!

[gpc]

All right, will do. Thanks for the advice cavdad45, a 10 min phone call could say me a world of problems.