HS 81R running problems

[avinit]

Hi, its not a chainsaw but wasn't sure where else to post this ?

 

Basically it starts after a bit of effort. It will run but only for 5 seconds or so. It will restart after choking again. It will keep running if I keep pressing the fuel bubble.

Sounds like a fuel problem but don't really know where to start.

 

Any advice would be appreciated.

[dan494]

Does it run with the choke half on? I had one like this, didn't get to the bottom of it as it got stolen 😡

[spudulike]

Sounds like it isn't getting enough fuel so check the fuel filter isn't clagged up, make sure the fuel line isn't holed or split - especially where it pushes through the wall of the tank, make sure the carb internal gauze strainer is OK, check the height of the metering arm, condition of the pump diaphragm, condition of the metering diaphragm and it should be one of these things.

 

Not sure if the impulse line is a rubber separate one or internal to the carb but check this is clear as well or the pipe isn't split if it has a separate one.

[avinit]

Hi, replaced fuel lines, cleaned out carb, same problem???

There does seem to be liquid / fuel?? Coming out of the exhaust if that means anything?

I'm at a loss.....

[arbmark]

mine was doing the same. got the local stihl dealer to put a new carb in. boom it's like new again.

[spudulike]

Hi, replaced fuel lines, cleaned out carb, same problem???

There does seem to be liquid / fuel?? Coming out of the exhaust if that means anything?

I'm at a loss.....

 

If there is fuel dripping out of the exhaust, the needle valve is leaking or is being held open by incorrect metering arm height or hardened metering diaphragm.