Is it possible to vent one of the newer EPA compliant non-vented fuel tanks?

indyboy

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Mar 15, 2012
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I have both plastic and metal 6 gallon portable boat fuel tanks with no manual vent. What a pain in the rear!...especially on a hot day when the plastic ones swell up. They both can have vapor lock issues while the engine is running if the fuel cap is fully tightened but will leak fuel due to splashing if the caps are loose. Is it possible to drill a tiny hole in the cap to provide a vent? Does anybody have a home-grown fix that works? Thanks in advance for any and all ideas. Happy Boating! :joyous:
 

jimmbo

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May 24, 2004
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Drill a hole in the cap, tap it and screw in a vent valve/petcock
 
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indyboy

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Not sure the cap material is thick enough to tap but I was thinking about drilling a hole, attaching a nut to the underside with epoxy or J B Weld and threading a screw in from the top with a rubber or nylon washer that can be loosened to prevent vapor lock while running the motor and tightened during transport to avoid fuel splashing out.
 

indyboy

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Hey Jimmbo...your suggestion got me thinking.. NAPA Auto Parts sells a brass petcock valve that only requires about a 1/8 inch hole be drilled into the gas cap for it to fit. It is also threaded so just add a nut on the bottom and maybe a couple rubber or nylon washers if you want and it's fixed. The petcock is only $4.75. Looks like the perfect fix. Thanks again. :joyous:
 

isaksp00

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I might use Goop brand glue instead of epoxy, if you go that way - it is a bit more flexible and may be less prone to cracking than epoxy. I think it is fuel resistant.
 

indyboy

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Actually Permatex intake manifold sealant is probably the best....I have sealed countless V-8 Chevy intake manifolds with the product...totally oil and fuel resistant.
 

alanfox55

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Nov 17, 2011
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You can purchase a new cap with a manual vent. You can get one here at iboats for $11.
 

indyboy

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Wow! Thanks for info...didn't know the EPA allowed vented replacement caps or that a "snap-in" vent was available. :joyous:
 

indyboy

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Hey alanfox55...what did you type in on the parts registry for this site to find vented caps? I typed in everything I could think of and found 1 snowmobile gas cap but zero portable marine tank vented caps.
 

indyboy

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After lengthy discussions with 2 IBoats Tech representatives the only retro-fit vented cap they offer is a snowmobile tank cap. That is all I found on their site also. The vent you seem to be referring to is a vent that has to be drilled into the tank...It's not a cap.
 

JimS123

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The current tanks are useless safety hazards. The mandate is state-wide, not federal. I found a vendor on EBay that sold the old vented caps, so I bought a bunch of them for future use. Most vendors will not sell to a mandated state, but this guy had no such requirement. After receiving them I bought a bunch more, so I guess i'm good for life now.
 

alanfox55

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