Gas String Trimmer Stops Running

[billy3p]

Make- Homelite
Model- Bandit SX 135
i was given this unit when a young teenager's parents bought him a replacement for his summer lawn care business. I assume it was due to intermittent operating issues but I got two growing seasons of use from it with little issues. Now, I am unable to get it to continue to run after less than 10 minutes of starting and using it. It is my understanding this model was made with two different walbro carburetors? If so, how can I determine which kit I would need to search for and order if I want to consider rebuilding the carburetor? Or, any input as to what else might be the issue is appreciated.

 

[sgkent]

Remove the gas cap, put it back on and see if it starts. If so then the tank vent system is not properly venting. On some it is a small breather hose that can swell shut. Also clean the air filter. Every small motor like that I have had die after running because of a bad carb diaphragm does so after a few seconds, not ten minutes.

 

[7394]

And if that doesn't help, dump a capfull of Seafoam in the gas tank, shake well & try again.

 

[StarTech]

Make- Homelite
Model- Bandit SX 135
i was given this unit when a young teenager's parents bought him a replacement for his summer lawn care business. I assume it was due to intermittent operating issues but I got two growing seasons of use from it with little issues. Now, I am unable to get it to continue to run after less than 10 minutes of starting and using it. It is my understanding this model was made with two different walbro carburetors? If so, how can I determine which kit I would need to search for and order if I want to consider rebuilding the carburetor? Or, any input as to what else might be the issue is appreciated.

Remove the carburetor and looking the Walbro model numbers. From there post them and someone should be able to look up the carburetor and give the correct kit numbers.

But is likely a WT-458-1 (WT-458A) which uses the D20-WAT gasket and diagram kit or the K20-WAT carburetor repair kit.

 

[billy3p]

I used this string trimmer on 04/11/22. After about 15 minutes of run time it starting losing power like it was choking out. I adjusted the butterfly position and was able to get it to operate at full speed for about another 5 minutes before it started losing power again. Is it possible the issue is that the butterfly valve or choke control position lever is closing the butterfly valve due to vibration?

 

[billy3p]

So today while using this string trimmer I could see the choke lever handle move from a position where the unit was operating as it should to a position where the engine started losing power and choking due to what I assume is the butterfly valve inside the carb closing. Any suggestions on how to fix this issue are appreciated and thank you.

 

[StarTech]

Most 2 strokes have a plastic flap that covers the tiny carb opening connected to choke lever, behind the air filter. This is how it chokes. You gotta think of something like a piece of painters tape to put on & keep choke lever in open position, after running. ..

No butterflies in these carbs. Suggest: You remove the air filter cover (1 screw) & take out filter & see the choke flap & arm, & you will better understand,. Do not re-tighten cover up too tight.

Then how does it control the engine speed?

And btw the way according to the following it does have both a throttle vane (butterfly) and a Choke vane (butterfly).

And carburetor is still available from Walbro.

and choke shaft itself is available.

If you remove the choke shaft there is usually a steel ball and spring that detent the choke shaft.

 

[7394]

Then how does it control the engine speed?

My Bad I was referring to my vintage Honda Tiller, that has a barrel in carb opening to accelerate..

 

[billy3p]

Uploading a few pictures of the carb. The choke shaft looks to be made out of brass maybe? Anyone here seen one like it and removed the shaft?

 

[StarTech]

An older Walbro carburetor. I had a few of them. Still uses a spring and ball to lock it in place and brass shaft will wear out the dimples.