View Full Version : How long do you flush for?

07-05-2002, 04:27 PM
Members - how long do you flush your outboard for after use in saltwater? I normally go for about 2 minutes but notice time varies greatly between boat owners. ;)

07-05-2002, 06:08 PM
2 minutes doesn't sound very long. I park the boat, attach ears and start flushing. At this stage i jump in the boat and take out what needs to be taken out. Put away old bait, hang up rods ( after a wash ), clean out rubbish, take out extra clothing, etc etc. Put rags under tell tale, so water fills bucket they are in. When the bucket is full, you have flushed enough.

Basically. you have to wait until the thermostat opens to make sure of a proper flush. 8)

08-05-2002, 02:12 AM
I had the thermostat cut so it is fully open at all times now as it was stuffed. I used to do it on my old holdens. Do you think in this weather we have in SE Qld it should be a problem on 2 stroke outboards? I flush for about 10 minutes aswell. When I had a look at the housing around the impellor a lot of crap still gets stuck in there even after flushing.
Cheers Luke

08-05-2002, 05:13 AM
5-6 minutes but depending on the water pressure too long on muffs doesn't do the water pump much good. Muffs don't do the water pump much good anyway but there's not a lot of other alternatives with some setups.

Cheers, Kerry.

08-05-2002, 05:40 AM
Hi Paul,
After a trip to that salty stuff I always bring the boat home & dump her straight into the river near home to give it a good wash out. Also give the trailer a good dunking too.
Anyone reckon a motor needs flushing after a run in freshwater?


08-05-2002, 12:55 PM
ever heard of anyone flushing in motor coolant? One of the managers at work has a drum of antifreeze/antiboil anti corrosion coolant at home that he drops his motor into after flushing with the rabbits ears for about 3 mins. He's always done this and to every motor he's had. A feew weeks ago, he had to take the head off for some reason and not a trace of corrosion anywhere (motors 10 yrs old too). I didn't beleive him till I went over there and had a look for myself. It's true, no corrosion.
I'm gonna do the same, just looking for a suitable drum to store it in.
Bill :o

08-05-2002, 03:30 PM
My yammie has one of the self flussing attachments, usually
plug hose in when i get home, give the boat a soap down
then run the ears (bottle on side type) #with some Macs
to help fight the corrosive. . Fitzy id still flush as you dont
know whats been sucked through her . I'd say most freshwater dams have percentage of saline content in them that my thoughts.

09-05-2002, 09:09 AM
My neighbours usually determine how long I flush for.

I have a 25 year old Evinrude 140hp that chews a fair bit of juice as well as being quite noisy - she also blows a bit of smoke when she's out of the water.

The neighbours two story house is very close to our fence line so when I flush the noise and smoke drifts straight into their loungeroom.

Other than the heat of the water coming out of the outlet pipes - I usually decide when she's had enough when the neighbours close their window/blinds or come out onto the back deck and glare at me.

As for the fresh - flush - I have a 4 hp Johno that's two years old which has only been used in fresh water and I've never flushed it yet.

Had it serviced after coming back from Tassie recently and the mechanic assured me it was as clean as a whistle.

Regards Bugman

09-05-2002, 02:01 PM
2 minutes is way too short a time to properly flush the motor. Like Phill said, I wack the muffs on and leave it running while I clean the rest of the boat - 15 to 30 minutes and up the anti on the revs to a fast idle for about 2 mins after it has been running for 5 or so mins. This will make sure that you get water circulation right through the galleries.

My previous boat had a 90hp Mariner which had a great idea - a top down flush system whereby you connected the freshwater to a hose connection that went in near the top of the motor. Strangely enough, my new boat has a Mercury 115hp - 4stroke and this motor does not have that feature.

Muffs are ok but to really get a good flush you should use a drum if possible. Some marine dealers can supply a HD Vinyl flushing bag which you slip up around the leg with a strap over the top. When filled with water it acts like a drum.

A bit of extra care now can save you HEAPS later!!!



09-05-2002, 03:52 PM
I try for 5 mins it depends on others who use my club 's ramp we have a 10 min limit on the wash bay if crowded i spend 5 max if only one there i'll flush it longer .


09-05-2002, 05:35 PM
Fisho, I usually flush my motor for 5 to 10 minutes using an ouboard silencer (for the neighbours). I find that with the silencer the water will pump out through the top outlets just under the cowl (as it does out on the water) which it won't with the use of muffs only. I haven't had any problem with corrosion in the 20 or so years I've had Johnson motors. I never flush out after being on fresh water impoundments. I fugure that's as good as flush as it's ever going to get. I'd imagine that drums are a better option but the water in them couldn't be used over and over as I'd imagine it would oil up and become contaminated with other exhaust particles.

25-10-2005, 02:30 PM
Hi guys i am new to this chat site but davo has the best idea. you need to use a flush bag why , because we manufacture them but ours dosnt need a strap over the top and also its the quietest way to flush and our bags have an attachment on the bottom to fill the bag, and when u are finnished the water can be gravity fed back to your garden..The bags are available from most dealers.

25-10-2005, 06:34 PM
Greg01- Those flush bags are a great idea I baught one at the tackle and tinny show. I use it all the time. I run a solution called salt X through the motor at the end of flush then I connect the hose to a big tub and use the flush water with the saltX in it to wash my reels and Minn Kota. The only criticism I have of the flush bag was that when I bought it the stitched seams were coated with some sort of sealent like silastic on the inside of the bag, little pieces of it were floating everywhere so I scraped of all the sealent so as it would not be sucked into the motor and now its fine.

25-10-2005, 09:05 PM
I have had outboards for more than 30 years. I'm no expert and I'm not a mechanic, but I have found and been advised to never rely on muffs or screw in's to flush your motor. Mine are always flushed in a drum, which I don't allow the telltale to bleed into. I also add about a teaspoon of Turtle Car Wash to the drum of water. I disconnect the fuel line AFTER 20 mins and let the carbies run dry. Never, ever, touch wood,( :P) have I had a problem with cooling or anthing associated, included corrosion and I only have to change impellers after about 5 years.
This is just what works for me and what time and experience has proven to me.
Each to their own.


25-10-2005, 09:30 PM
Just wrote a reply to this but then the screen refreshed for some reason and didn't save anything. That's twice tonight now.
In short, I flush the same as Phill, and do recommend flushing after a run in dams.


26-10-2005, 10:46 AM
Flush mine on the muffs for 10 mins max. Seems to do the trick so far.

26-10-2005, 10:50 PM
Prob do the 50 merc for about 4-6min. By the time get her runnin let her idle, throw her into forward/reverse, muck around. Then usually give the head a wash n a spray with lanolene.
Seems to do the trick

27-10-2005, 10:27 AM
Reel Nauti, I used to disconect the fuel line but was advised by the mechanic not to do so. Possible problems with no lubrication on the cylinder walls if the pre mix is not being injected or with oiling up system with unburnt oil in injector models.

I flush mine at the ramp straight out of the water for max 5 mins but generally around 2 minutes. This way salt does not get the opportunity to dry and build deposits inside the system and is flushed right out. If I have any doubts about whether it has been long enough I leave it to my tongue to ensure that no salt is in the tell tale. It is much more sensitive to any salt in the water then any other instrument. Mechanic has not noticed andy build up at regular services.

27-10-2005, 11:51 AM
Bowser, you are right. Older pre-mix motors can be run dry on fuel but oil injected ones can't as when the fuel runs out the engine is still pumping oil straight in. I learnt this a few years ago !

28-10-2005, 03:04 PM
At my last service I was told the thermostat was stuck half open. Mechanic said it would be because I wasn't flushing for long enough - I was doing about 3 minutes. He suggested 10 was the way to go.

BTW - I thought we had Kerry back when I read through this post - till I realised it was a resurrected post. Pity - where are ya Kerry ?

28-10-2005, 07:37 PM
I flush my for ten minutes I put into cut off bin on two part's put outboard in bottom bin and take off the foil then pull up the oter half most out board leg is in water like being out the water ( i don't trust muffs) I do this before heading out and back from days fishing give motor good flush and running temp before heading out (this is wear I pick up a problem with my outboard nearly over heated a fair while ago so ten minutes is good

gunna I though the same as you kerry was back we all know you got rid of him (2 foot chop)


29-10-2005, 01:28 PM
who knows what the answer is? I flush for around 5 minutes on muffs. I haven't flushed after my last trip (about 2 weeks ago) - haven't had time - will do today. Boat mechanic told me previously not to worry about it too much - deals with plenty of people who never flush their motors or only every now and again and hasn't come across many problems. Told me outboards are a lot tougher than you think (2 strokes).

I usually make sure I flush immediately after the trip (pull up the driveway) - that way the outboard is still hot/warm - I figure 5 mins is okay then.

30-10-2005, 03:37 PM
Coming from family that loves to fish and boat, I can remember asking my dad the same question.
He told me to taste the water coming out of the motor... When it's fresh, give it a few minutes and it's done! ;)
:'(I don't recommend tasting it..... It's a bit hard to tast the salt over the two stroke! ;D