flush engine

[fisheymikey]

force125 1988

I was wondering if there is a way to flush the engine. I have seen calcium build up on other ppl engines and want to do some preventing measures before I have a actual problem. my engine does not over heat so I think its flowing correctly.

is there a addictive I could add to the bucket when I run the engine so I could get the calcium out?

clr, simple green etc...

I also see BIG square bolt I could remove on the port side... is that the side we could do a flush

thanks

 

[jpwilly]

Re: flush engine

I have heard of people using a small tank like a tote or bucket and submersible pump or mini fountain pump to circulate mixed water and some sort of mild acid (Vinegar, CLR, etc) to effectively flush the motor. You'd need to rig it up and let it run for an hour or so. Then you need to flush with water and possibly add an acid neutralizer like baking soda to the water and run again. I'd use straight water to finish rinsing out the motor.

Don't get wild with the acid - aluminum heads and acid don't mix well and it can pit the metal. I'd remove the TSTAT and any parts you don't want acid running through i.e. the lower unit impeller etc. make sure you test your mix on something else first if you can even vinigar will etch metal.

My advise is don't do this unless you need to. If you don't have an overheat problem you may want to just leave it alone.

 

[pnwboat]

Re: flush engine

If it isn't broke, don't fix it. If you're in fresh water, it generally isn't an issue.

I assume you are referring to the square head pipe plug that screws into the adapter plate on the port side? Yes this is the water passage that comes from the water pump tube that goes to the bottom of the engine block. I removed the original plug and put a brass fitting there for my water pressure gauge. A real pain to get to. See Picture below.

 

[fisheymikey]

Re: flush engine

ok then I wont do that...

pnboat I already have a telltail installed... I iwanted to install a pressure guage if possible but I read its not recommended due to loss of pressure to the engine...

do u recommend I install one?

thanks

 

[MickLovin]

Re: flush engine

I heard Salt-away is a good product to do you flushing with.

 

[pnwboat]

Re: flush engine

A water pressure gauge will not reduce water pressure to the engine. It's pretty much personal preference as to whether or not you want to install one or not.

 

[Jiggz]

Re: flush engine

As PNW mentioned, if it is not broke don't try fixing it. However, if the need ever arises you have to flush, personally, I would go with what we used on naval ships condensers, radiators and other cooling systems, which is citric acid. The solution is 10% citric acid and the temperature should be at least 120~130F. For an outboard engine, you will need a trash tote or can large enough to hold the solution and then ran the motor for at least 30 mins. Make sure the discharge solution also returns back to the can or tote for recycling back to the engine. You will need to use some kind of filter (cheese cloth or muslin bag) either from the suction side or from the discharge side of the motor's cooling system to prevent debris on going back into the system. The thing to watch for this kind of set up is the motor overheating. The motor can usually ran between 120~130 without sustaining damage. The advantage of this setup is you do not need an external source of heat to keep the solution hot or warm.

Another setup is the use of an external pump as previously mentioned but you will need a means to keep the solution at least warm or 120~130F.

As for solution, radiator flush usually also contains 10% citric acid so you can also use it to flush the motor.

 

[MickLovin]

Re: flush engine

Hey Jiggz could you use that orange cleaner? Or do you actually get citric acid.

 

[Jiggz]

Re: flush engine

Hey Jiggz could you use that orange cleaner? Or do you actually get citric acid.

We used anhydrous citric acid which you can buy from Amazon. Most of the time it is referred to as citric acid de-scaler used on coffee machines and the like. Of course, to use it on outboard motors or large condensers you will need higher concentrated solution, 10%, while those used on small appliances is probably less than that or maybe even down to 5%. Google cheapcitric dot com to get more info.

 

[jerryjerry05]

Re: flush engine

The build up??? isin't gonna be enough to worry about.
The big square plug.It's gonna be tough to remove.Don't try.
On the 88 there is a small cover on the lower front of the exhaust port cover.
Some have this,some don't.
Under this is a spring and plug.It's a pressure relief valve.
This will sieze after a while usually salt water is worse.
Don't worry about it.It will cool either way.Plugged or not.
The flushes and stuff to disolve would be needed from the begining.
Kinda like closing the barn door after the horse has escaped.
The thing to do is the exhaust plate,remove it periodically to make sure no sand/mud builds up there.
I've NEVER done this and NEVER worried about it.
The ones in my 88/85's were stuck.Don't know how long they've been stuck.It made no difference.