Parajet tank

[pete_b]

Due to the vent being in the cap and is only one way with the hot weather the fuel in the tank expanded and without anywhere else to go it forced its way through the carb.

I removed my plug today (inverted simo engine) and had about a cup full of fuel come out.

Anyone else had problems???

Pete b

[Guest]

Thats an interesting one Pete. I had noticed a pressure release sometimes when opening the cap but had not thought any more of it. Could that result in fuel accumulating in the crankcase? I think I have heard that this is not good in a two stroke as it can cause damage if it exoplodes there when you start the engine? do you know about this?

Do you have a workaround?

[pete_b]

Hi Francis

It could very easily fill the crank case with fuel if it pushes its way through the carb as it did on mine (walbro 37)

I have drilled and taped a fitting in the opposite side to the pick up pipe and have a vent pipe going up to the top of the main frame.

It will be best to have either an empty tank or a full one as air will expand the most when heated.

Pete b

[Guest]

I bought a fuel tap from a lawnmower shop for a fiver which as well as stopping this problem also stops the problem of the fuel lines draining back into the tank over time leading to excess air in the lines. It also means that if your kill switch fails inflight you can stop the engine by shutting off the fuel supply.

[pete_b]

I bought a fuel tap from a lawnmower shop for a fiver which as well as stopping this problem also stops the problem of the fuel lines draining back into the tank over time leading to excess air in the lines. It also means that if your kill switch fails inflight you can stop the engine by shutting off the fuel supply.

Good thinking

as long as you remember to turn it off when you land.

I'm getting on a bit and the memories not to good now

Pete b

[Guest]

...as long as you remember to turn it off when you land...

Yes the problem is that it needs you to remember!

[Guest]

Both good solutions by the sound of them.

The vent is a pipe from the top of the tank to the top of the frame? I had similar on my old PAP as standard fit. It had a bicycle valve in the end so when you lay the motor down for transport no fuel could leak out, but then in a hot car you are back to fuel pushing up the supply pipe when you have closed the valve! Also in the PaP fuel line there was a squeezing bulb for priming, I gues this would expand with fuel before getting all the wau=y up to the carb on that machine?

The tap in the fuel line will result in high pressure in the tank when hot? Presumably the tank and lid are up to that? Where is the tap positioned? I like the idea of another kill method.