Hisun fuel tank vent problem!!!

[strike250]

Hello once again, this time I want to bring to your attention a problem that I found out the hard way. On one of our previous trips to Dumont Dunes, my son had the great opportunity to roll his Hisun Strike 250 at very low speeds, no damage to him or the vehicle and it landed up right as well. but one thing we noticed was that fuel had poured all over the passenger!!!. Once we got back I looked at it and found the fuel tank vent was of such poor quality that it broke at the fuel tank. Not sure if it was from the roll over or just from being made from poor quality plastic. Well, I found a great long lasting repair and wanted to share it with you all. It is something that is found is pretty much most off road race vehicles. I installed a roll over valve in place of the fuel tank vent. I am including some pics to show you. In the event we roll it over once more, the vent valve will automatically shut off the flow of fuel. It has a ball valve in it and when upside down, it blocks the flow of fuel so that it can't pour out all over the persons in the vehicle and have a potential fire! It is gravity controlled. The valves are low cost at about $15 or so. Cheap insurance when it comes to safety for sure. I cleaned out the hole where the previous fuel tank vent was. I removed the fuel tank pump/filter assembly. I then drilled out the hole just smaller than the ball check valve. I was able to reach into the fuel tank to catch any plastic that the drill might push into the tank as well. I used a fuel resistant sealant on the threads as well. I used a 1/4" NPT thread fuel tank check valve with a 5/15 hose barb. This is a much better product than the OEM product. I would recommend every one install one of these for safety if they get a chance. Or at the very least inspect your fuel tank vents. No one wants fuel leaking on them in the event of a roll over.

[Travis]

OH MY! Glad to hear you son is O K . Poor Quality Hisuns!

[Rangerider45]

Good fix and explanation. 

My Hisun Sector 750 overflows if I fill the gas tank too much. I was thinking of putting a dirt bike, two-way air valve on my gas tank overflow tube.  That way it would ventilate the gas tank, but does not let fuel flow out.

[strike250]

That is another great idea, I would only tell anyone to watch out for cheap "aftermarket" clones as they sometimes have a 'reliability' issue. But if you feel you have a quality one, by all means, install it. The idea is that when it is over, it will prevent liquid from spilling out. You can test anyone of these items by using a plastic water bottle and a rubber tube installed on the bottom end. just turn it upside down, and see if it stops the water from flowing out. If it does, then you are good to go. I just used a higher priced unit sourced from a reliable race source. But there are a lot of good quality aftermarket anti roll valves out there you can choose from. Good luck and have fun!

Matt

[Orebonder]

Vent?... On my Hisun vector 250, I get an air pressure release when I open my gas tank fill cap...is that normal?

[strike250]

I would check to make sure the vent hose is not pinched. It sounds like the fuel tank is building up pressure while the engine is running. I would gain access to view the fuel tank and observe and inspect the entire fuel tank vent hose. Look to see if it is pinched or blocked at all. This would cause the problem you are talking about. You should not have the pressure when removing the fuel fill cap.