Freestyle Cart Tank Venting Q??

[NVJAY775]

I have an issue going on and it's probably my fault lol! But not sure yet haha! I set this tank up the same as my old except I ran my return line to the bottom of the tank, and my primer runs off that line.

So I have one line going from tank to carbs.
Return line coming off carbs back through the top of the tank and then to bottom of tank, with primer line coming off this.
Stock SJ tank vent hose with one way valve.

I installed Cold-Fusion fuel and primer lines and LOVE IT. Awesome to work with. But I have an issue... I haven't ridden in a few weeks. When I finished the last ride, I still had about 1.5 gal fuel left in the tank. Yesterday I was just messin around and turned on my bilges and smelled fuel. Hmmm. Took off the hood and almost all of the fuel was out of the tank and in the bottom of the hull. I noticed a leak at the primer T fitting. I unscrewed the fuel tank cap and it was pressurized a bit. A bit of an air release when unscrewed.

So just for grinns, I pulled the tank and tested it for leaks and found no leaks.

I never had a pressuring issue from weather with my old tank. Did it have an air leak somewhere relieving the pressure possibly?

What's the proper way to vent a tank and is the one way valve totally necessary? Is there another option, or does the tank need that one way for pressure? I feel like a dumbass for asking, but it just seems that the pulse line is what works the fuel pump, so the tank should be fine being vented with some other kind of filter... But I am not sure. WTF OVER!!?? I'm confused..

And on a side note I don't like my primer T very much. Anybody know of a good one to use? Mine lacks barbed ends except for the primer line itself. The fuel line ends suck wanker.

Thanks guys.
Jay

 

[D-Roc]

My old 550 tank never held pressure. My new cart tank does. I dunno.

 

[scotts2t]

One way is necessary to let air in to replace the fuel being burned by your motor so you dont get an air lock. it lets air in but does not let the pressure out built by fuel fumes. Pressure is necessary to keep your carb pumps loaded with fuel. Air in fuel lines could cause lean running conditions.

 

[NVJAY775]

One way is necessary to let air in to replace the fuel being burned by your motor so you dont get an air lock. it lets air in but does not let the pressure out built by fuel fumes. Pressure is necessary to keep your carb pumps loaded with fuel. Air in fuel lines could cause lean running conditions.

I understand that, but this pressure is high enough to push the fuel past fittings when sitting. It's just annoying that my old tank didn't have this issue. I don't want to have to unscrew my tank cap when the ski isn't running. that's a serious pain in the arse.

 

[D-Roc]

It also strains the needle ans seats. I usually crack my cap when not in use during the week

 

[NVJAY775]

Well I did some testing tonight.
With my tank cap completely off, my carbs pull fuel fine without the tank being pressured.
Tank cap off, motor idling, the return line filled pretty quickly.

Thoughts on the tank being pressured. I would think this would make jetting more of a pain, due to fuel pressure fluctuations. Or just inconsistent performance in general, although maybe not totally noticeable.
Also hard on the needle and seats. If the needle and seats are in bad shape, It wouldn't take too long to get fuel past them and filling up the cases with fuel.

Long story short, I punched a small hole through my one way vent valve, in the return line. Should work like a champ. Consistent tank pressure, still flows the some as far as letting air in.

I must have had some sort of an unknown air leak in my old tank. That's all I can think of.

Thanks for the input fellas! Appreciate it all.

 

[steve-uk]

hey Jay are you a brit... cos you sure do curse like one... :biggrin:

 

[orangefinger]

I have an issue going on and it's probably my fault lol! But not sure yet haha! I set this tank up the same as my old except >> I ran my return line to the bottom of the tank, and my primer runs off that line <<<

Why run the return line to the bottom of the tank ?? If you accumulate pressure in your tank it will squeeze it out the return line >> into the primer which will then leak, unless your tank is properly vented, I think this can even happen then...that migth explain your dilema ?

Btw stop firing up the ski in garage lets go ride....

 

[NVJAY775]

hey Jay are you a brit... cos you sure do curse like one... :biggrin:

Haha! What the he77 did I say lol?! Not a Brit, but I sure am curious what I said. Or is it just that I ramble on too much lol?!

I have an issue going on and it's probably my fault lol! But not sure yet haha! I set this tank up the same as my old except >> I ran my return line to the bottom of the tank, and my primer runs off that line <<<

Why run the return line to the bottom of the tank ?? If you accumulate pressure in your tank it will squeeze it out the return line >> into the primer which will then leak, unless your tank is properly vented, I think this can even happen then...that migth explain your dilema ?

Btw stop firing up the ski in garage lets go ride....

Yah yah... I want to ride trust me! The weather today hurt me deep dude..

The return line runs in the top like normal, but inside the tank I ran a weighted line to the bottom of the tank, just like a reserve line in a standard tank. But I did run a low loop on the return line to the bottom of the hull, just to make sure I will always have a primer shot of fuel available. And that's where my primer T ties in also. At the bottom of the loop. The loop is actually more of a sag lol.