CCV Fuel Tank questions

All, I bought an ALRC log booked 88in trialer last year, it had it's first detailed scrutineering session earlier this month and one issue was the lack of external vent on the fuel tank. I've attached a few photos but my understanding is that I need to seal the fuel filler cap so that it does not vent and then add an external vent pipe with a non-return valve. All thoughts welcome, especially if they come with part numbers or links to the bits I'll need!

Many thanks in advance.

Richard Stone

Try theok 4x4 Cheltenham

Or try wkd 4x4 off road solutions they really good matt dillon has been well help full.

dandit1200 said:

Or try wkd 4x4 off road solutions they really good matt dillon has been well help full.

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Thank you

Richard all you need is a ball bearing and a brake pipe fitting. My cap has a pipe fitting attached and a ball bearing in so when you roll the ball drops and seals. When your righted the. Ball bearing allows air in so the tank doesn't collapse.

In t

jai_landrover said:

Richard all you need is a ball bearing and a brake pipe fitting. My cap has a pipe fitting attached and a ball bearing in so when you roll the ball drops and seals. When your righted the. Ball bearing allows air in so the tank doesn't collapse.

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In that case what about a motor cross tank breather the after market ones with the none return valve built in for that exact reason to stop fuel leaking one you when you crash .my yamaha yz has one fitted as standard .The bike is buried in the workshop ill try get it out an take a pick .surely you could attach my pipe to the breather pipe some how with a reducer and then you have a one way valve .eBay sell them for less than 5er. Feel a numpty for not thinking if it before.

Bit more than a fiver then but that's the first one I looked at

jai_landrover said:

Richard all you need is a ball bearing and a brake pipe fitting. My cap has a pipe fitting attached and a ball bearing in so when you roll the ball drops and seals. When your righted the. Ball bearing allows air in so the tank doesn't collapse.

Click to expand...

Thank you, that sounds simple, can you let me see a photo? The brass tube on the underside of my filler cap does have a ball in it held up with a spring. I'm not sure what the black tube does, that has a mesh inside I think.

To be fair the aluminium non return one way valve above seems an easy fix for £3

jai_landrover said:

To be fair the aluminium non return one way valve above seems an easy fix for £3

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And it looks cool .....I'll be needing stuff like this for my winch challenge truck I'm building (comp bug) soon as I have finished the series 2a

Umm bling is usually heavy,

CCV and comp safari keep the weight down.

How did you get on with the one way valve??

I've just removed one from a CCV tank as it totally screwed with the mixture expecially at idle on a hot day with fuel expansion plus the hot fuel returning from the carbs warm. I had to junk it in favor of a roll over ball valve.

I've fitted the one linked below, have only had the vehicle out once since then and that was on a simple off-road course, not a CCV but seems fine (first CCV outing is on Sunday!), my V8 is an EFi, not carbed though.

http://www.demon-tweeks.co.uk/motorcycle/fuel-accessories/mocal-in-line-fuel-tank-breather-valve

Thats the correct type anyway. The simple one way valves are not ideal as the tank cannot breath. I don't think it will do much on an EFI anyhow but it deffo pressurised the tank and threw loads of extra fuel in when warm very noticeable at tick over after a run or warm day.

I also had issues with the pickup pipe being at the rear corner i did a roundabout and it run out of fuel. So we fixed that aswell it still had 2 gallons of fuel in. This is a new to me second hand motor just sorting the niggles its had put on it over the years. No CCV booked yet but Its road legal so will take it for a spin at some point, either a CCV or laying out the next local one.
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Well the national Comp safari is booked @owl

The ball bearing in the copper tube in your cap is the non-return valve.