unavailable
22.05.2021 9:31:08
The problem is that the checkball inside the valve gets worn and tends to jam thus restricting the flow of fuel.
See full version: Sympton of bad anti siphon outboard
The problem is that the checkball inside the valve gets worn and tends to jam thus restricting the flow of fuel.
The symptoms of a bad anti-syphon valve are, hard starting, surging RPM's while under way, hesitation or backfiring upon acceleration and lack of wide open throttle (WOT) RPM's.
The solution is to replace the faulty anti-syphon valve.
That said, many customers elect to just knock out the ball and spring or replace the valve fitting with a standard hose barb. This can improve performance and is less troublsome HOWEVER the owner should be aware that he/she is modifying the manufacturers design and taking some risk. Fire or explosion can result from fuel leaking into the bilge. Although it is a rare failure, fuel lines can break or come loose and allow fuel to syphon into the bilge area thus causing damage, injury or death.
The purpose of the anti-syphon valve is to prevent fuel from syphoning into the boats bilge in the event of a break in the fuel line.
So at this point you're trying to remove the pickup itself. and it ain't budgin'. At this point, we'd start to use terms like "heat" and "torch" and that kind of stuff. but it's a fuel tank, and a poly one at that!
Glad you got it out! Don't worry, you can coax those vise-grips out.
2006 1720cc Thanks for input!
The purpose of the anti-syphon valve is to prevent fuel from syphoning into the boats bilge in the event of a break in the fuel line.
The solution is to replace the faulty anti-syphon valve.
That said, many customers elect to just knock out the ball and spring or replace the valve fitting with a standard hose barb. This can improve performance and is less troublsome HOWEVER the owner should be aware that he/she is modifying the manufacturers design and taking some risk. Fire or explosion can result from fuel leaking into the bilge. Although it is a rare failure, fuel lines can break or come loose and allow fuel to syphon into the bilge area thus causing damage, injury or death.
Boat Manufacturers are required by law to install an anti-syphon valve in the boats fuel system. The valve is usually a hose barb fitting with a checkball and spring inside. It is usually mounted to the fuel tanks pickup tube where the rubber fuel line attaches. Some anti-syphon valves are mounted to the fuel filter assembly on the outlet side.
After refilling the tank, engine performace is fully restored. Ran 20 minutes at 4,700 RPMs without any fuel starving, then shut down to idle and resumed normally maneuvering. There are no restrictions in the lines other than the anti-siphon valves, so they will be replaced with straight through barb fittings.
Am planning to knock the ball assembly out of both valves and pull the tubes. Am leaving town for a few days. When we return, I will pull them and give you an update.
As an aside, I knew a guy that worked in the marine industry for 50 years. When he was working at a high end fishing boat manufacturer, he had a chance to deliver a new boat. The first thing the dealer did was send the mechanic out to remove the anti siphon valves and replace them with barbed fittings. The mechanic would throw the valves as far out in the water as he could so nobody would reuse them. The dealer said the valves caused more problems than they solved. He was shocked because a big part of his job was to ensure the boats were built in compliance with regulations. They dealer was more concerned with his customers not getting stranded 80 miles off shore. He used his contacts in the industry to find me a new anti siphon valve. The size I needed was unusual. It is in my tool box somewhere. I used a barbed fitting temporarily so I could get back on the water. It's been ten years, I'll get around to it one day. here