View Full Version : Water pump

05-15-2007, 10:58 AM
"I ave a yanmar ysb 12, single cyl, (1977) that leaks water out of the scupper in the shaft housing. Replaced water and oil seal. There is a gap between the bearing washer and the water seal. What keeps the oil seal secured to the back of the impellar housing (negative pressure?) I am on the hard and am using fresh water hose. Still leaking water from the scupper. Am I using to high pressure from the water hose ? Impellar working well and shaft not damaged"

05-23-2007, 09:28 AM
"Change your seal and place open side of seal towards the impeller on the water side. Slide your thumb nail across the shaft where the seal sits, if you feel the groove then replace the shaft.
Never use a city water supply hose to feed your engine as the pressure will dis-lodge the seal.
Fill a bucket and let the engines impeller suck up what it needs. Full Sails .... Regards Ron"