Locking Fuel Cap

[sunbyrned]

Hi everyone!

Can anyone recommend a locking gas cap for a 2012 242? I always fill it up for the winter and for the past two years my first trip out only has half a tank. Obviously something is happening while in storage. I’ve attached a pic of what the tubing looks like for the gas. There’s a lip at the bottom so I have to buy the right thing to accommodate that lip I believe. Thanks for your help!

 

[FSH 210 Sport]

Hi everyone!

Can anyone recommend a locking gas cap for a 2012 242? I always fill it up for the winter and for the past two years my first trip out only has half a tank. Obviously something is happening while in storage. I’ve attached a pic of what the tubing looks like for the gas. There’s a lip at the bottom so I have to buy the right thing to accommodate that lip I believe. Thanks for your help!

I’m pretty sure the best way to do this is with a whole new fuel cap / thru hull fitting.

 

[sunbyrned]

I’m pretty sure the best way to do this is with a whole new fuel cap / thru hull fitting.

Thank you! I’ll look into that. That sounds like the way to go. In the meantime, I just ordered this cheap anti siphoning device. This one goes in where the fuel cap is. They make others where it attaches to the actual fuel tank. That one seems better but I don’t want to go to that much trouble right now.

Amazon.com

 

[David Martin]

Good luck.......sounds like the storage facility guy keeps his personal vehicle full at the expense of his customers........shaking head now.

 

[sunbyrned]

Thanks! I keep it in my father-in-laws shed. This will be my third season doing that. The first time it happened I convinced myself I must not have filled it up, which would have been odd. So I made it a point to remember that I filled up last season. She had a half tank in her on my first outing. So, it’s definitely happening in storage. The shed is on a remote site with no cameras and his help uses that shed for their tractors and such. Pretty sure that’s what I’m supplying each year. Going to look into the thru hull gas cap lock that @FSH 210 Sport recommended.

 

[biffdotorg]

For those that are shopping locking gas caps, have you actually tried siphoning fuel out of their boat? From what most have discovered, it is next to impossible. I have heard of a check valve that prevents it. But the only check valve I saw was on the breather hose.

But it is near impossible to get a siphon hose down that fuel hose. Many that wanted to drain their tanks ended up pulling the fuel sender off the top of the tank to access the fuel.

 

[Joatmon]

Maybe not on a Yamaha, but easy to do on a Scarab. Someone siphoned 20 gallons when my boat was at storage facility. I found he cap open and foot prints on the fender. The manger said he would check the cameras but after never did. I moved to another safer facility. I installed a round head stainless steel Torx screw with the stud in the middle that requires a special Torx tool to remove. Drilled hole through outer edge of cap into the cap housing. Cannot grip the screw head with pliers either. Not 100% secure but makes me feel better. I hide the tool in the boat and keep one in my tow vehicle. Not so much as loosing gas but someone adding something to the tank and ruining the engines. Yes, I'm a little paranoid, but it is based on past history.

 

[FSH 210 Sport]

For those that are shopping locking gas caps, have you actually tried siphoning fuel out of their boat? From what most have discovered, it is next to impossible. I have heard of a check valve that prevents it. But the only check valve I saw was on the breather hose.

But it is near impossible to get a siphon hose down that fuel hose. Many that wanted to drain their tanks ended up pulling the fuel sender off the top of the tank to access the fuel.

Well, sunbyrd had thief’s figure it out.

The main reason I want a locking cap isn’t to protect from fuel theft, it is to prevent vandalism. One of our members here had some asshat fill his tank with water.

 

[sunbyrned]

Well, @biffdotorg is correct. They do have a check valve. Now I’m really puzzled. Ha! Any ideas on how the gas can be escaping? Vapors?

 

[sunbyrned]

Maybe not on a Yamaha, but easy to do on a Scarab. Someone siphoned 20 gallons when my boat was at storage facility. I found he cap open and foot prints on the fender. The manger said he would check the cameras but after never did. I moved to another safer facility. I installed a round head stainless steel Torx screw with the stud in the middle that requires a special Torx tool to remove. Drilled hole through outer edge of cap into the cap housing. Cannot grip the screw head with pliers either. Not 100% secure but makes me feel better. I hide the tool in the boat and keep one in my tow vehicle. Not so much as loosing gas but someone adding something to the tank and ruining the engines. Yes, I'm a little paranoid, but it is based on past history.

That’s a great idea too. Thanks for sharing.

 

[Joatmon]

I may be wrong but I believe a check valve would be on the fuel line from the tank to the engine fuel rail and or maybe the vent hose. Not the tank filler hose. Now the tank filler hose sometimes have a step or S shape to prevent a siphon hose from reaching the fuel in the tank. I know 20 gallons of fuel just didn’t evaporite within a week from my Scarab tank.

 

[sunbyrned]

Here’s a diagram. #26 is the valve. This one appears to be connected to the tank filler hose so maybe it’s just a different design than the scarabs.

 

[Joatmon]

Yup. I didn’t see a description for the details so I assume one of details 21-27 is the check valve. Nice. Maybe i should have looked at installing instead of using the tamper proof screw in the cap. What I don’t understand is if the check valve opens downward to allow fuel flow then why would a siphon hose not open the check valve? It would be hell to remove the hose though. Thanks

 

[sunbyrned]

I don’t know. But I am going to lock it down somehow this time and see if that changes things. Who knows how they’re doing it but I’m convinced they are.