fuel shut off valve for string trimmer

[Yardguy]

I have a Stihl FS55 string trimmer. I want to shut off the gas to run the carburetor out of fuel after each use.

The two tubes that stick out of the carburetor for the fuel lines are about 1/8 inch OD, so the fuel lines are about 1/8 inch ID. Is there a fuel shut off valve that can work with 1/8 inch ID fuel lines?

Thanks,
Yardguy

 

[mechanic mark]

Not necessary if you use high octane gas with Stihl 2 cycle mix & Stihl fuel treatment per instructions, for safety, after using & engine cools down, remove spark plug boot & tuck away from plug.

 

[7394]

Yardguy- Are you having a carb issue that requires the gas be cut off ?

I've never seen a shut-off that small, but there could be some..

 

[Yardguy]

Not necessary if you use high octane gas with Stihl 2 cycle mix & Stihl fuel treatment per instructions, for safety, after using & engine cools down, remove spark plug boot & tuck away from plug.

My problem is in my reply to 7394.
Thanks,
Yardguy

 

[Yardguy]

Yardguy- Are you having a carb issue that requires the gas be cut off ?
I've never seen a shut-off that small, but there could be some..

Yes, the engine on my Stihl string trimmer kept starting OK but wouldn't keep running. I disassembled the carb and there was gunk in it. Cleaned the carb and reassembled. Now engine runs fine.

I had the same problem with my John Deere lawn mower. I installed a fuel shut off valve and let the mower run out of gas after I use it. Never had a problem with the mower after that so now I want to do the same thing with my Stihl string trimmer.

Thanks,
Yardguy

 

[bertsmobile1]

With the garbage we get sold now days pretending to be petrol, it is a good idea to always run a engine dry rather than turning it off as the few seconds of lean , hot running burns off the crud on the plug.
Allowing it to run without firing may coat your plug with unburned fuel, which is conductive.
AFAIK there are no fuel safe valves in that size.
I advise customers to tip out the left over fuel then start the tool, it will run for a few seconds then run out of fuel.
Fuel is best stored in an air tight container as well which the tanks on tools are not.

 

[Yardguy]

With the garbage we get sold now days pretending to be petrol, it is a good idea to always run a engine dry rather than turning it off as the few seconds of lean , hot running burns off the crud on the plug.
Allowing it to run without firing may coat your plug with unburned fuel, which is conductive.
AFAIK there are no fuel safe valves in that size.
I advise customers to tip out the left over fuel then start the tool, it will run for a few seconds then run out of fuel.
Fuel is best stored in an air tight container as well which the tanks on tools are not.

I just started pouring out the left over fuel from the tank and running the engine until it dies, after I cleaned the carb. I'll continue to do that and keep an eye out for a fuel shut off valve in the proper size.

Thanks,
Yardguy

 

[bertsmobile1]

I just started pouring out the left over fuel from the tank and running the engine until it dies, after I cleaned the carb. I'll continue to do that and keep an eye out for a fuel shut off valve in the proper size.

Thanks,
Yardguy

Sounds like a good plan.
A little messy but most trimmers & saws have a vent in there which will leak fuel it it ends up being upside down.
"Fuel" has a very small amount of light highly volatiles to facilitate cold starts and this quickly evaporates leaving fuel which is impossible to start with.
When sealed tight in a can, less of the volatiles will evaporate.
I now sell customers a 1 Liter ( Quart to you ) mixing bottle and tell them only to make up the litre, use it all up then make some more so it is always fresh.

most of us have a big 1 gallon can we mix fuel in then it sits in therefor one a year before we get any where near the bottom of the can which with modern fuel is a very bad idea.

 

[Ric]

It's not necessary to run a Fuel shut off, the machine wasn't designed to have a shut off or it would have one. Stihls require at least 89 octane gas and most run 92 or 93 octane. If you run the high octane gas and the Stihl HP ultra and it's not necessary to run any other stihl treatments. The Stihl Ultra already contains fuel stabilizers as do most of the two stroke oils.

 

[Ric]

Sounds like a good plan.
A little messy but most trimmers & saws have a vent in there which will leak fuel it it ends up being upside down.
"Fuel" has a very small amount of light highly volatiles to facilitate cold starts and this quickly evaporates leaving fuel which is impossible to start with.
When sealed tight in a can, less of the volatiles will evaporate.
I now sell customers a 1 Liter ( Quart to you ) mixing bottle and tell them only to make up the litre, use it all up then make some more so it is always fresh.

most of us have a big 1 gallon can we mix fuel in then it sits in therefor one a year before we get any where near the bottom of the can which with modern fuel is a very bad idea.

I don't think wasting fuel sounds like a good plan and I've never had a piece of equipment leak for being upside down. As far as fuel mix goes, I'll mix 20 gallons at a time and I've never had fuel go bad and have never used any type of stabilizers, only what comes in the oil itself.