Hey Guys,
I'm desperately trying to get my 6hp Johnson to pump water. Why it is'nt pumping is a mystery to me and to the outboard mechanics I have taken it to. I hoping there's someone here who might have had the same problem and found the solution...So firstly the history goes like this: The boat was beached and so the impeller sucked up a whole bunch of sand, causing a blockage, causing the motor to stop circulating water, overheated and stalled. The good news was after later inspection, no real damage had been done. Except the tip of one of the impeller blades had broken off and lodged in a channel in the powerhead, causing another blockage. That was then cleared, and the impeller replaced.
Here's what I have already tried or checked:
Thermostat has been taken out, so it's not that.
I've made sure the copper pipe meets the housing properly when assembling (the seals are good)
the bolts holding the impeller housing down where looseish, so I drilled and re-taped 6mm metric bolts
I have taken the lower unit and submerged it in water, turned the shaft with a drill, and it pumps water with no problems
I have connected a water hose to the copper pipe coming from the impeller and watched the water flow freely through the powerhead and come out the pee-hole.
Therefore the issue seems to somehow be related to the exhaust gases forcing the water out the impeller housing, thereby stoping it from priming/pumping. My mechanic seems to think that the housing is not properly sealing with the lower unit. So we have ordered a complete new impeller housing kit. However I don't think this is the issue, Firstly because there is an incredibly tight seal there, and second because there is absolutely no seal where the shaft enters the housing. So even with a perfect seal between the housing and the lower unity, air could still easily go through at the shaft. However to complicate things, if this is the issue...then how did it work for years before, without such a seal? Just to rule the option out, I am busy making a seal out of silicon for between the shaft and the houseing.
But then I realized that in actual fact, where the shaft enters the housing, it's usually submerged, and perhaps it's the water that keeps air out of the impeller housing. I'm not really sure...
I ran a pipe from inside the exhaust chamber, down through the exhaust vent at the bottom end and up again to the powerhead. I made sure this pipe was completely un-obstructed and that air could flow between the exhaust chamber and outside, unhindered. I thought if the exhaust gases could escape via the tube, thereby negating the necessity of the the exhaust gases being pushed through water, and a pressure being built up in the exhaust chamber, it would solve the problem. But this did nothing...
Please help
I'm desperately trying to get my 6hp Johnson to pump water. Why it is'nt pumping is a mystery to me and to the outboard mechanics I have taken it to. I hoping there's someone here who might have had the same problem and found the solution...So firstly the history goes like this: The boat was beached and so the impeller sucked up a whole bunch of sand, causing a blockage, causing the motor to stop circulating water, overheated and stalled. The good news was after later inspection, no real damage had been done. Except the tip of one of the impeller blades had broken off and lodged in a channel in the powerhead, causing another blockage. That was then cleared, and the impeller replaced.
Here's what I have already tried or checked:
Thermostat has been taken out, so it's not that.
I've made sure the copper pipe meets the housing properly when assembling (the seals are good)
the bolts holding the impeller housing down where looseish, so I drilled and re-taped 6mm metric bolts
I have taken the lower unit and submerged it in water, turned the shaft with a drill, and it pumps water with no problems
I have connected a water hose to the copper pipe coming from the impeller and watched the water flow freely through the powerhead and come out the pee-hole.
Therefore the issue seems to somehow be related to the exhaust gases forcing the water out the impeller housing, thereby stoping it from priming/pumping. My mechanic seems to think that the housing is not properly sealing with the lower unit. So we have ordered a complete new impeller housing kit. However I don't think this is the issue, Firstly because there is an incredibly tight seal there, and second because there is absolutely no seal where the shaft enters the housing. So even with a perfect seal between the housing and the lower unity, air could still easily go through at the shaft. However to complicate things, if this is the issue...then how did it work for years before, without such a seal? Just to rule the option out, I am busy making a seal out of silicon for between the shaft and the houseing.
But then I realized that in actual fact, where the shaft enters the housing, it's usually submerged, and perhaps it's the water that keeps air out of the impeller housing. I'm not really sure...
I ran a pipe from inside the exhaust chamber, down through the exhaust vent at the bottom end and up again to the powerhead. I made sure this pipe was completely un-obstructed and that air could flow between the exhaust chamber and outside, unhindered. I thought if the exhaust gases could escape via the tube, thereby negating the necessity of the the exhaust gases being pushed through water, and a pressure being built up in the exhaust chamber, it would solve the problem. But this did nothing...
Please help