Raw water blockage

[Dave-R]

I have had many boats, but never a problem like this. The boat is a 17 foot Regal with the Volvo Penta 4.3 and a SX drive. I am having a heck of a time getting water from the muffs to the crankshaft pump. I took of the pump hoses, and could not get any water to the pump suction. I have 2 sets of muffs, and they are both new and very tight. One even has duel inlets. First thing I tried was back-flushing from the pump suction with a hose. Yes I could get flow backwards but not as much as I thought it should. So now I thought maybe the power steering cooler could be partially plugged, So I undid the upstream cooler hose and back-flushed it for 10 minutes. I then tried the muffs again with the cooler hose off but could only get flow if I used a lot of pressure on the muffs. It's only 2 feet of head pressure to the cooler from the muffs. I am perplexed. Tomorrow I will pull the drive and try to flush it. Anyone ever have a problem like this? Thanks Dave-R

 

[Scott Danforth]

pull your PS cooler and remove the debris that is most likely in there.

if something large enough is in there, it would act like a check valve

 

[Dave-R]

Thanks Scott: My blockage is even before the cooler. I Thought at first it has to be the cooler, but I pulled the cooler inlet hose off and tried the muffs again with the same results. I then back-flushed from the cooler inlet towards the outdrive. I had the garden hose clamped tight and it did flush that way but seemed restricted. I guess today I'll pull the drive and see if I can see anything obvious. I will also try to get water from the cooler down to the pump also, but I need to find out why I'm having such a hard time getting water to the cooler inlet. Really got me baffled Thanks Dave

 

[Dave-R]

After pulling the drive off then using the muffs, I can get plenty of water up the drive. I also get plenty of flow up the from the transom. I think I will buy a new OEM impeller and start over. Dazed and confused.