What and where is the popet valve on a 70 HP Yamaha(1988). I read this in another post relating to overheating at idle speed, but no explanation where poppet valve is located.<br /><br />"The poppet valve and seat would be the next thing I would check. Disassemble and clean the plastic valve and the rubber seat very carefully. I would also put the gasket back on the water pump. If the pump does not seal correctly, it will cause the problem. The poppet valve not sealing good or a water pump not sealing correctly will either one give you the symptoms you are describing. When you have the pump body off place on a flat surface to be sure it is not warped any. I use white lithium on the o ring in the pump to hold in place while assembling. Silicone and similar gasket materials often will often keep it from sealing. Hope this helps."
