How to clean cooling system of 9.5 Sportwin

Have a 9.5 Sportwin. 9922B 1973. Have replace waterpump, thermostat and still runs hot. Next step is cleaning out cooling system. Believe it is filled with salt. Lower end had sand falling out of it when 1st dropping foot. Will Lime Away work by pouring it down the thermostat port. ( After removing the thermostat of course. Also replaced head gasket and milled down the surface smooth.

Re: How to clean cooling system of 9.5 Sportwin

In your dreams

Re: How to clean cooling system of 9.5 Sportwin

I wondered the same thing!

Re: How to clean cooling system of 9.5 Sportwin

the best is to pull of the powerhead, change all gromets, gaskets at water jacket

Re: How to clean cooling system of 9.5 Sportwin

HI loco. I don't think you'll get quite that lucky unfortunately. You'll probably want to remove the LU and connecting a garden hose to the copper water uptake tube on med pressure. This should help flush any large solids out of the pipe. You should see the water come out of the main exhaust port and/or thermostat housing if you have the cover removed. Watch out, or you'll get wet too. You should also be able to do the same thing from the top down by slowly pouring water into the t-stat housing and watching it exit out of the exhaust. If the the small passage leading to and from the t-stat housing seem clogged you can use a piece of stiff nylon such string such as piece of weed eater string and/or a guitar string to help poke out and debris. Assuming you can run water through the system as a whole, there may be hope. When you removed the head gasket, did you see any major deposits around the cylinders in the water passages?

Re: How to clean cooling system of 9.5 Sportwin

I was able to clean mine out by taking the L/U off and head gasket, and running pressurized water through from all of the openings. Give it a try before you go tearing into the whole engine. These little motors pack a little punch considering they only weigh around 60lbs.!!!

Re: How to clean cooling system of 9.5 Sportwin

It was a little crusty and I used sand paper to clean it up. I have replaced the head gasket and water pump and she still runs hot. So I am guessing the water flow is not where it needs to be. It spits water but then it gets real hot and I have to shut her down. I put a new t-stat in as well. I will try flushing from both ends and see what happens.

Re: How to clean cooling system of 9.5 Sportwin

loco50 said:

It was a little crusty and I used sand paper to clean it up. I have replaced the head gasket and water pump and she still runs hot. So I am guessing the water flow is not where it needs to be. It spits water but then it gets real hot and I have to shut her down. I put a new t-stat in as well. I will try flushing from both ends and see what happens.

Click to expand...

Yeah that sucks that it is so blocked up man. Try shooting water into every orifice that you have. I shot it up the exhaust tube, into the coolant jacket (covering the cylinders), up the water input tube and all that mess. Mine was a salt water motor too. Fortunately for me though, some dummy didnt run it in sand and salt water and just say F it and let it all dry up in there. It was still pretty blocked up in there though. I ran a coat hanger little by little into all of the ports, and day by day let water and CLR soak deeper and deeper until I finally had free flowing water through the whole water system. Worked for me......

P.S. I actually like it that these motors have the exhaust water exit from so up high. Lets you know that you are DEFINATELY flowing water, unlike the newer 9.9's that have the thermostat after the telltale hole, meaning that if the thermostat seizes up you still flow water from the telltale.

Re: How to clean cooling system of 9.5 Sportwin

I have run my 115hp crossflow in salt water forever and have used Salt away at every flushing and at least once a year I use a barrel with the lower unit submerged in a salt away concentration and let it run for 15-20 minutes.
I just pulled the power head for rebuild and didn't find a spot of salt in it anywhere. Give it a try, I think you will see a difference.

Larry