Flushing I/O used in salt water (not with Perko Flush-Pro)

[lenny2113]

I have read many threads about this. <br />Concluded that Perko Flush Pro is not something I would want to use. "West Marine customers" feedbacks are not that great to say the least.<br />MSD "Guardian" setup is close to $500 per engine, and I have two engines. Do not want to spend that much.<br /><br />I am going to go with brass open/close valves and hope that I will not forget to open it back once I flush the engine. I figured as I get older I may need to custom order a sign that would read "Close garden hose valve, Open raw water intake" . But I think I am good for now.<br /><br />Here is what concerns me:<br />Water pump impeller is there in the outdrive to draw raw water into the cooling system. Having the open/close valve in the close position directly at the water intake hose will prevent raw water entering the cooling system of the engine (which is exactly what I need).<br /><br />Would this create a problem for the outdrive impeller It will be turning and pushing the water into a blocked passage. <br /><br />Would this overheat the impeller housing causing damage to rubber impeller? <br />Anyone sees any issues having this setup for flushing?<br /><br />Thank you.

 

[AaronG]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

What you are thinking won't work if the engine is running. Then again neither will the flushpro. To be able to fully flush the engine, you need to set up a way to route the water from the alpha's pump overboard, and hose water to the engine. You'd need two y valves. I think its a bad idea to try to run the engine with the drive's raw water pump blocked off, and who wants to mess with all those valves every time you come back to the dock. <br /><br />I have a flush-pro. It works fine, but you are really only flushing the manifolds and risers. The quality of the flush pro seems fine, but the real downer is that you can't really flush the engine since the thermstat blocks the flow. <br /><br />I saw somewhere an actual mercrusier part that either replaces the thermostat housing, or connects to it. It allows you to flush the motor properly. I'm going to try to find that, and install it this winter.

 

[lenny2113]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

AaronG, Thank you ror your comments.<br />That is why I have posted this question. I intend to run the engine while flushing. Once the temperature will reach 140, my termostat will open and the engine will be flushed.<br />I am ready to take a drawback of "messing with valves" rather then have my engine sit full of salt water. <br />Perko Flush PRO - 3 bad out of 4 feedbacks...<br /> Flush Pro review <br /><br />Please, give some more opinions:<br />Blocked raw water passage from the outdrive... Problem or Not?

 

[crazy charlie]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Lenny,where are you planning on tapping into???I had a boat with a single 5.7 and ran 2 heater hoses to the block petcocks and joined them at the ends to a y connecter and ran that to a water outlet I installed in the cockpit.With the motor off I would snap a quick connect ,put it on low pressure,and leave it to backflush while I cleaned up.I now have twin 5.0s and cant get near the petcocks so I tilt the drives up and reach down to the drives with earmuffs and do it the old fashioned way.Total of 10 minutes and I have to dry off each arm.Charlie

 

[AaronG]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

I read those reviews before. I wouldn't mind dealing with the thing needing replacement every other year if it flushed the whole engine. Too bad it doesn't. <br /><br />Try to find the mercrusier flush adapter. I think its fairly new. That looks like the ultimate solution.

 

[lenny2113]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Charlie,<br />I could tap to the water intake hose right as it comes from the drive. <br />I have to drop exhaust manifold of one engine to reach spark plugs on both engines. If I pull one engine out of the boat I could reach to petcocks of both engines <br /><br />My drives do not come out of the water as high as I need to reach. I see what you're saying. I would be able to do it if I back into the dock. It would be very inconvenient as I would not be able to reach the bow to wash the boat. I can reach transom from the inside of the boat. <br />If I am in the dock bow in, I cannot reach the drive. <br /><br />Do you think it would cause impeller damage if I run it with closed intake valve??<br /><br />Thank you!

 

[lenny2113]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

This is what I have in mind<br /> Flush

 

[crazy charlie]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

I would be more concerned with the normal flow WHILE you are running.It looks as if the flow may be a bit restricted as it narrows through the valves.You may wind up reducing the amount of water you cool with.Dont get me wrong,it aint that easy to get the muffs on by laying on my swim platform and reaching down ,but it IS simple.Charlie

 

[lenny2113]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

If I had swim platform I would be doing what you're doing and would stop bothering people <br />I have 1 1/4 intake hose. I would use same size valves to make sure there is no restriction of flow. <br />It is the back preassure at the pump impeller that I am concerned with.<br />Thanks.

 

[Scaaty]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Originally posted by Lenny2113:<br /> It is the back pressure at the pump impeller that I am concerned with.Thanks.

I know where your coming from with this. I have a 350 raw water pump off to the side of the motor, belt driven (Volvo leg-no impeller) and have wondered the same thing. I can pinch the hose with no problem, but wonder what the impeller is doing. If its cavitating, the air/bubbles could create a condition not good for the rubber blades. I also have drilled and tapped a female brass quick disconnect into the top on the thermostat housing (air fitting that I attach the male end with a PVC ball valve and hose fitting), and with this I also do something as similar as Crazy Charlie ""single 5.7 and ran 2 heater hoses to the block petcocks and joined them at the ends to a y connector and ran that to a water outlet I installed in the cockpit.With the motor off I would snap a quick connect ,put it on low pressure,and leave it to backflush while I cleaned up."" , but on mine, it only slowly flushes out the manifolds, which go south in salt a hell of a lot faster than any cast iron block. I also just trickle it in....no large pressure, as it just might possibly back up and get in the exhaust, filling a cylinder, hydrolocking, and now ya got real problems. Curious as to the conditions that occur with a blocked outlet on the impeller too, as I would like to block it off after the pump, and run water through my "flush device" with the engine running, but I have no idea either on the impeller impact.

 

[Scaaty]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Heres a picture of my crude, rude, but works good 'nuff to get the salt water in the man's a little less corrosive. I only run some fresh water (slowly) through if it won't be used in a week or more, otherwise best to just run it every 4-5 days, and that way it really cuts down on corrosion, as the running water breaks up the corrosion process...of course I have a thousand theory's about everything.... <br />

 

[Scaaty]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

And by the way, about 4 years ago, in a pinch, I used a steel quick disconnect for a kicker motor gas line on a rowboat, and still works fine to this day......

 

[lenny2113]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

I changed my impeller every fall. I thought about not doing this this year. Mostly because 2 years that I have been changing it it could have lasted for one more season. I wanted to be on the save side because the cost of pulling the boat out of the water is more then the price of a new water pump kit.<br />I am not too crazy about doing something I have no idea of the outcome. But it sure looks like if noone has the answer for

Do you think it would cause impeller damage if I run it with closed intake valve??<br />

I might as well try and let you guys know. <br /><br />Notice how this setup would work:<br />Close raw water intake and run the engine on fresh water will flush the block and manifolds. <br />Close the other end and with engine off flush the drive. I like this idea.

 

[Scaaty]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Go for it! Somebody has to be the first to find out what the impeller will do. I have a spare raw water pump, and when I get time (probably not until winter) I will set it up and do some experiments too

 

[crazy charlie]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Come to think of it, I seem to remember a setup like what you want to do Len.The difference is that you have to run a through hull off the valve set up so the water coming from the drive has somewhere to go.I know for a fact that you can burn an impeller from revving too high in neutral even though it is submerged.Based on that,I would assume that an impeller turning in the same small amount of water that the housing contains could possibly heat the water up too much and cause premature failure of the inpeller or housing.Charlie

 

[lenny2113]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Charlie, <br />You are right. That is what I am worried about. <br />Impeller creates enough friction to boil the water if it does not circulate. It will overheat the housing and may cause impeller to soften prematurely.<br /> <br />I should have a 3-way valve on the way in. Thruhull hose coming out of the third end of valve. That is going to be "water release". <br />As long as I remember which position of valve will do what Will need to stay sober enough for that <br />As I turn the water on and open valves, I may be able to judge by water coming out of my thruhull exhaust that it is safe to start the engine.<br /><br />I figure it will cost aroung $100 for each engine, but it will last a long time as it will be brass valves. <br /><br />Oh, I called Perko about "Flush-Pro" unit. They say it is not meant for I/O setup. It is good only for Inboard. It should be installed before the pump, that way with the garden hose attached to Flush-Pro it will not draw salt water in through the thruhull water intake.<br /><br />With the outdrive, there is pressure from the raw water intake created by impeller pushing water into the cooling system. Flush-Pro is NOT DESIGNED to close or partially close the water intake with the outdrive. This will only work if flushed with engine off. Otherwise, what happens is, salt water is still comming in mixed with fresh water. What good is it???... None IMHO.<br /><br /><br />My engines have never seen "Salt Away". There has not been a week I have not used the boat, but still it sits in salt water with the cooling full of salt. 2 seasons old manifolds are starting to rust. And it is 4 manifolds and 4 risers for me to change <br />Both engines are rebuilt 80 hours on one, 50 hours on the other. <br /><br />Brass valves !!! I am going for it. I just hope it does not start leaking from all the vibration and pounding. TOO MANY CONNECTION POINTS. <br />Flush <br /><br />Verdict: I/O guys !!! if you are flushing using Flush-Pro with your engine running... Who are you kidding

 

[lenny2113]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

Hey Charlie, <br />Water boils at 100 degree celcius that is 212F.<br />If it boils it evaporates as steem creating space for new water to come in. Oil if heated may reach higher temperature. Water will get to 212 and turn to steem. I am sure if I take an old impeller and boil it for 20 minures in the pot of water it will be fine. I am most likely right on the theory, but the aliminium insert of the impeller housing will get too hot from friction with impeller blades. <br />That was thinking outloud... <br /><br />Thank you!

 

[crazy charlie]

Re: Flushing I/O used in salt water (not with Perko Flush-Pro)

I am not always right but I am never wrong