Hurricane fuel tank vent

[subfixer]

My 2005 Sundeck 237 has trouble venting the fuel tank. I gets lots of tank burping while filling, causing backsplash at the fill connection. I cannot locate any fuel tank vent. Maybe the only vent is at the fill. Anyone know of a vent location and/or a remedy. I suspect this is contributing to a stalling problem that I am having.

 

[subfixer]

Re: Hurricane fuel tank vent

I looked further today and found no other tank vent. My hurricane has a Perko combination fill/vent connection mounted vertically high on the gunwhale. The vent hose terminates at a fitting in the neck of the fill tube. There doesn't seem to be a good vent path when the fill cap is installed. There is a drilled passage through the fill cap but on the tank side there is "purge tab" that closes the vent when there is pressure in the tank. I think it is supposed to be a flame arrestor but it looks like it will act as a check valve, especially if the vent isn't mounted horizontally so that gravity assists to keep the tab open. Also the drilled path through the cap looks to be sealed when the gasketed fill cap is tightened down. Has anyone had problems with these Perko combo fill and vents?

 

[NelsonQ]

Re: Hurricane fuel tank vent

subfixer....first welcome to iBoats. I'm not entirely sure of the brand of fill/vent on mine but my last two Hurricanes (2002 GS170) and my current (2010 SS 188) both do the backsplash when filling and I have to slowly fill the top part of the tank to prevent it.

 

[subfixer]

Re: Hurricane fuel tank vent

thx Nelson..........Apparently you are not having any sort of stalling/fuel starvation issues as I am. I am thinking that if I haven't got a great vent path than I may be drawing a vacuum in the tank, when I throttle up. I am powered by a yamaha F225 and ever since I installed a fuel/water seperator, I have trouble priming and get a stall during the first throttle up. After re-priming it usually starts and runs fine at all speeds until I shutdown again. Maybe a combination of greater fuel flow restriction due to the filter and a lousy vent path. I am going to bypass the fuel/water seperator and see what happens. I am also going to measure fuel line vacuum to see if I can detect any fuel restriction.

 

[NelsonQ]

Re: Hurricane fuel tank vent

subfixer.... no I'm not having fuel starvation issues. I know this will sound obvious and stupid but is the flow direction on the separator correct and are the proper inlets. Mine has multi inlets and you have ensure the right flow direction. (Again, I'm sure you've done this but worth mentioning) I think you're bang on your description to bypass the separator completely to isolate that problem. If so, you know that the restriction is or isn't because of the separator. Let us know the results.

 

[subfixer]

Re: Hurricane fuel tank vent

thx Nelson.....yes I have checked the seperator installation and a whole lot more. I have a post in the engine maintenance section, under the yamaha and Suzuki outboards. The threads have some pretty good info about fuel flow issues and expected fuel specs if your interested. I'll post the results of my troubleshooting.

 

[subfixer]

Re: Hurricane fuel tank vent

Fuel rail pressures (40#) and fuel suction vacuum (2.5") were all in spec. with or without the water seperator in the system and with or without the fuel filler cap installed. I permanently installed test tee's so that I can check these values again when waterborne. I am looking into another fuel filter and canister located at the rear of the engine cowling. My service manual or maintenance guide doesn't mention it. It may be a vent for the VST. It looks like I am headed for VST cleaning and injector cleaning. More info on my Post (F225 stalling) in the Yamaha and Suzuki Outboard section of the Engine Repair and Maintenance forum.