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fuel shut off valve for string trimmer

#1

Y

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


#2

M

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.


#3

7394

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..


#4

Y

Yardguy

mechanic mark said:
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.
Click to expand...

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


#5

Y

Yardguy

7394 said:
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..
Click to expand...

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


#6

B

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.


#7

Y

Yardguy

bertsmobile1 said:
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.
Click to expand...
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


#8

B

bertsmobile1

Yardguy said:
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
Click to expand...

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.


#9

Ric

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.


#10

Ric

Ric

bertsmobile1 said:
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.
Click to expand...


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.


#11

Y

Yardguy

Ric said:
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.
Click to expand...
I run Shell V-Power 92 octane gas in our car and all lawn equipment. I was going to buy some Stihl Ultra so I just did a search on amazon for "Stihl ultra oil". The 3 hits that came up all say "Discontinued by Manufacturer".

I wanted to install a fuel shut off on our Stihl string trimmer since our John Deere lawn mower had ongoing carb fouling problems and installing a fuel shut off valve on it and running until the engine dies solved the problem. It starts within 3 pulls every time now.

Thanks,
Yardguy


#12

Ric

Ric

Yardguy said:
I run Shell V-Power 92 octane gas in our car and all lawn equipment. I was going to buy some Stihl Ultra so I just did a search on amazon for "Stihl ultra oil". The 3 hits that came up all say "Discontinued by Manufacturer".

I wanted to install a fuel shut off on our Stihl string trimmer since our John Deere lawn mower had ongoing carb fouling problems and installing a fuel shut off valve on it and running until the engine dies solved the problem. It starts within 3 pulls every time now.

Thanks,
Yardguy
Click to expand...


The Stihl HP Super was discontinued, the one in the black container not the Ultra, I just purchased the Ultra last Monday for $55 a gallon. I run the Sunoco 93 in everything. Their has been several places like Amazon that have discontinued their sales of the Stihl oil because they couldn't come up with a deal from stihl for their oil. Stihl has added a HP Ultra High performance oil, They have that online but I have yet to see the stuff at the dealership.


#13

Y

Yardguy

Ric said:
The Stihl HP Super was discontinued, the one in the black container not the Ultra, I just purchased the Ultra last Monday for $55 a gallon. I run the Sunoco 93 in everything. Their has been several places like Amazon that have discontinued their sales of the Stihl oil because they couldn't come up with a deal from stihl for their oil. Stihl has added a HP Ultra High performance oil, They have that online but I have yet to see the stuff at the dealership.
Click to expand...
You're right. Although I did a search for "Stihl ultra oil" on amazon, taking a second look now I see that the 3 "hits" are actually the Stihl High Performance oil, not the Ultra. No Ultra oil listed on amazon. I'll look for the Stihl Ultra in local stores.

Thanks,
Yardguy


#14

exotion

exotion

Running the machine dry can be worse than gunk in your carb. Parts that require lubrication in your carb can dry out then you have bigger problems. I would replace the carb and fuel. Leave fuel in the machine and run it every couple weeks...


#15

Ric

Ric

exotion said:
Running the machine dry can be worse than gunk in your carb. Parts that require lubrication in your carb can dry out then you have bigger problems. I would replace the carb and fuel. Leave fuel in the machine and run it every couple weeks...
Click to expand...

With all the Handheld equipment I run 2 stroke and 4 mix I've never ran a carb dry.


#16

Y

Yardguy

exotion said:
Running the machine dry can be worse than gunk in your carb. Parts that require lubrication in your carb can dry out then you have bigger problems. I would replace the carb and fuel. Leave fuel in the machine and run it every couple weeks...
Click to expand...

Thank you for sharing your perspective,
Yardguy


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