Strimmer & hot weather issues.

[ipbr21054]

Strimming for a while this weather & I can see the strimmer is going to stall.
Trying to give it some revs doesn’t seem to work but just bogs down.
What I found does work though is to stop the machine & undo the fuel cap. Start it again & away I go for say half an hour.
What’s happening here then by me undoing the fuel cap & doing it up again ?

 

[lostinthelight]

There is a breather valve/vent in the cap or tank that lets air in as fuel is used so a vacuum doesn't form in the tank.
Yours appears faulty which you've proved when the cap is unscrewed it released it....If you Google fuel tank vent for your make of strimmer you should see a picture of it

 

[Burnerman]

McCulloch perhaps? Often there's a flattened rubber tube valve in the cap which is supposed to let air in and doesn't.
John

 

[Harry Bloomfield]

Strimming for a while this weather & I can see the strimmer is going to stall.
Trying to give it some revs doesn’t seem to work but just bogs down.
What I found does work though is to stop the machine & undo the fuel cap. Start it again & away I go for say half an hour.
What’s happening here then by me undoing the fuel cap & doing it up again ?

They is a vacuum forming in the fuel tank, due to it using fuel. There is supposed to be a vent in the tank cap - perhaps the vent is blocked.

 

[ipbr21054]

Its a Titan.
Ive now found it thanks.

The fuel tank just has a rubber grommet with 2 holes for the pipes.
Supply & return.

The valve you mention in actually in the lid itself.
From underside the cap i pused using a small screwdriver & out popped a rubber thing & something that looks like a cigarette filter.

The cigarette filter is quite hard,clean underneath & dirty to the outside.
The rubber thing has a 2mm hole etc passing through it to then the section where the rubber actually touches itself creating a closed seal.
The way it is fitted & i have 2 of these & both the same i dont see how when the tank vapour locks this seal opens.
I say that as looking at it i would say its a one way thing.If i was to fit it the other way then the pressure would go up the 2mm hole then this currently rubber closed seal would be forced open to release it.
The way it is how does this even open under pressure i mean i dont see how its even possible.

Should i be looking for a different type of valve to fit in the cap or please advise.
Also remember both the cigarette filters are hard & not spongy

 

[ipbr21054]

Should i invest in these as i see a hole in the top.
What do you think ??

 

[Harry Bloomfield]

If i was to fit it the other way then the pressure would go up the 2mm hole then this currently rubber closed seal would be forced open to release it.

The idea is it doesn't release under pressure, it releases under vacuum. As you consume fuel from the tank, air has to be able to get in, or you get a vacuum which will prevent fuel flowing to the carb., as you have found.

 

[ipbr21054]

Ah right i now understand,hence why that seal is fitted the way it does.

So should i purchase the 2 caps as shown above as these obviously arent working

 

[conny]

For a fiver it's worth a go so long as they don't allow your fuel to spill through or allow it to evaporate.

 

[ipbr21054]

Ok I will order.