1800 Challenger Siphon issue

[Jim Bennin]

This past weekend I noticed my bilge pump running more than usual. Upon opening the bilge area, I noticed water entering the space via the engine siphon hose at a low rate. It even flows while engine is stopped and kids are swimming and continues to flow. I can understand why it would run while engine is running, but while stopped and off??? Any ideas?

 

[Scott E]

are you talking about the hose that connects to the jet pump? I had a 2001 1800 with the Mercury motor, and remember there being a siphon hose, but can't recall if there was a check valve inline. When the engine is running is there still water coming into the boat?

 

[Jim Bennin]

It does appear to flow when engine is running. Not sure on the check valve.

 

[Bilmon]

On the Mercs at the high point of the siphon hose there will be a plastic connector, This connector has a tiny and I do mean tiny air hole in it, if this gets plugged water will siphon into the boat when stopped No check valve that I'm aware of

 

[Jim Bennin]

One other issue that may not be helping is that I believe my reverse gate is out of adjustment which sends a good sized plume of water towards any tubers or

 

[Jim Bennin]

Just returned to the lake and it appears to have been running all week. The pump dumps water about every 10 to 20 minutes. Siphon end is still pushing water, how can this happen when nothing is running and its in shallow water? A bit baffled

 

[Bilmon]

If the siphon break [the small air hole] is plugged it can siphon water back into the boat once the motor is stopped because the pickup end of the siphon hose is in the lowest part of the hull below the water line . If nothing else just plug it off, its not really needed, just supposed to help get the last little bit of water out. When the boat is running the pump creates suction to drain water from the bilge when you shut the motor off it needs the air hole to break the siphon or it will just reverse its flow back into the boat