Reply With QuoteI only use fresh water for the old black max. Usually I go via the rowing club here and dump the old girl in the fresh water and let her run for 20 min. never had any over heating problems as yet
Yes, I use one or more of these products when I flush my motor.
No, I don't use these products when I flush my motor, but I know the products exist.
I wasn't aware these products were available.
I never flush my motor, so why would I use a salt prevention product?
Has anyone worked out if it is a detergent, cutting oil,acid etc. Have always meant to grab a sample off a mate and stick a pool test strip in it to see if it is alkaline , acid or whatever and see if it changes when fresh water is added? Mate has inboards on a mooring and we keep forgetting to use one of the treatments on one heat exchanger and just fresh water from the tanks on the other and see at the end of 6 months if there is any change in the build up in the exchangers but they run at so low a temp it may not be a good example.
There are so many very strong commercial scale removers for boiler tubes etc that do not eat metal ( in theory) and they are some alkaline, phosphoric acid or very dillute HCl acid that removes lime scale but not sure about salt as suck. We have used it before on old saltwater cooled diesels and they have got a huge amount of silt and rust scale out of the motors but they ae heavy , cast and have heaps of metal in them. .
It is a odd one as with all car motors they are running them hotter to meet emission controls but you can't do that with outboards with salt water as above X degrees you start to get scale from evaporation on hot stop starts forming.
I only use fresh water for the old black max. Usually I go via the rowing club here and dump the old girl in the fresh water and let her run for 20 min. never had any over heating problems as yet
20 minutes - god it will be worn out. Maybe 5 or so but 20 is just global warming and oiling plugs or a less minutes with a bit of load on the prop will warm her up and flush it out .Originally Posted by justlovefishing
I have had a number of outboards in my 40 years of boating & fishing and I have only ever flushed using ear-muffs and tap water until the water comes out warm (10 minutes or so).
Some of the Johnson outboards I owned survived over 30 years and still ran cool so long as the impeller was in good order.
The other thing I do is run all the fuel out of the carbies, so when it stops that is it.
Another reason I haven't bothered using additives as it takes long enough to clean up after a fishing trip as it is without mucking around with flush tanks etc.
Do you mean warm in the tell tale? My Yammie 115 2 stroke doesn't seem to ever get wam even after 15 mins on raised revs on muffs.
My evinrude 90 is the same Wal, my theory is the combined pressure of the muffs & the pump is enough to open the poppit valves causing enough water flow to never get the motor hot even with the thermostats closed.
I know for a fact that at high speed the OMC thermostats close down due to increased ram water flow opening the poppits.
If you think of it check it on the water when you first start it up, see if the telltale warms up then goes cold when the thermostats open.
I'm still looking for a tub to run mine in at home.
Yeah I thought a spare wheelie bin cut down would be ok but it's too small to fit leg in. Bought a pop up bag on spec and its too small too. So still on muffs.
My tell tail does warm slightly, just enough to de-solve any salt I assume. I do use a plastic drum cut to fit around the outboard leg to test run after servicing etc. Usually you can pick up a 200lt plastic drum for $10 or so.
The main thing using muffs is not to over rev your outboard as that is the quickest way to blow up a motor.
Thanks Allan. I have read of a runaway engine.... but don't understand how it happens. In any case I doubt I push it anywhere near fast enough when on muffs to be an issue. but I will now err on the slow side. Whereabouts have you seen drums?
I think you just have to keep an eye out as I did see a sign on the side of the road the other day, someone selling plastic drums, forget where it was though as I have one I didn't pay much attention. Sometimes see them on Gumtree.
It's best to keep as much hight at the back as you can though when you cut it down or the water all shoots out the back when you engage forward gear. I normally cut a square section out to fit around the mount on the boat and keep plenty of hight at the rear.
Speaking of run away engines, many years back working at North Pine Motors in Petrie when they had the Suzuki outboard dealership, we had a 50HP on a boat with the muffs on and it reved to infinity until the crank broke at the base of the fly wheel. Yep mechanics ducking and running in all directions. And it only took seconds for it to happen.
Run aways happen when a motor runs hot. It gets so hot in the combustion chamber that a spark is no longer needed to set off the fuel air mix so even when you turn off the ignition on a 2 stroke the motor keeps running or even when you pull the plug leads off. Can also happen with motors with carbon deposits on pistons that glow red hot and keep the process going. The only way to stop them is throw a rag into the carby airbox to stop any air getting in.
Having a run away in a diesel is something you want to move away from. If they blow a turbo and oil goes into the inlet they just keep going and going un governed. I once saw a large pump tear itself off its foundations as it "ran away" and a cool old bloke casually stuffed his flanny shirt in the intake while we were running away pulling the decompression levers one by one. . Balls the size of basketballs that old bloke. some motors in big gensets have emergency shut down shutters , dampners or even co2 systems to stop a run away getting more air.
Here is a example
Its a landrover so you know it isn't tyre smoke. Years ago there was footage of a huge v16 railway diesel electric engine exploding as a run away on Utube. Now I would have been with a mile and you saw the engineer running away . I wouldn't have been the camera guy to save my life knowing how much spinning metal was going to come out at warp speed. .
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