Internal Engine Zinc (sandy substance)

[Howard]

When changing the zink in the water jacket on my 1978 8HP yanmar, I stuck my finger in the hole where the plate that holds the zink fits and noticed a sand like substance in the bottom of the water chambor. This is right next to the Kingston Cock, near where the hose from the water pump enters the water jacket. I never did this before, although I change the zink each year. Th 8 HP is raw water cooled. Could this be sand that was sucked into the engine or is it the corsion remains of the old zinks? The sand is soft and can be moved around with my fingure altough I could'd get it out because of the angle.I can't take the side plate off of the motor right now and thought to use a shop vac with a small flexible tube to vac it out? I assume that I should remove the sandy deposites.I never had any problem with overheating or water discharge. Any suggestions ?

 

[Roland]

Sandy zincs

Howard, a couple of years ago I had to pull my YSB-12 and remove the head. In the process, I was able to get a good look at the water jacket. Since it is run in salt water there was the predictable build-up of minerals but not enough to restrict the water flow. I was able to scrape what I could and vacuum it out. If you are running in salt water, more than likely that is what you are feeling in the jacket. Since the deposits are mostly calcium, you could try running some white vinegar through your system to break it up and flush it out or if you are really brave, you could try muriatic acid and flush it out very quick as it will react with (destroy) metal. You do however, run the risk of loosening a piece big enough to cause a major block somewhere domn the line. My advice (for what it's worth), if it ain't broke, don't fix it. -RolandS/V Fraulein II