038AV Super problem.

[Maxparnell]

Hi Guys and Gals,
One of my two 038AV Supers has developed a strange problem.
It only wants to run with the H screw on the carb almost fully closed.
I thought maybe it was a problem with the carb and tried the carb off another working saw and found it still had the same problem; with a bit of fiddling around I worked out that I could make the saw work pretty well using either carb if i almost completely closed the H screw on the carb.
Has anyone come across this before and can tell me what the likely issue is?
Thanks

 

[HarleyT]

Clean air filter?

 

[Maxparnell]

No the air filter is completely clean and as far as I can tell the impulse hose is connected and I don't think that the rubber boot between the carb and the cylinder is holed either..........it also has a new fuel hose and fuel filter on it.

 

[CausticUC]

Does it make a difference if you turn it on it's side and shake it?

 

[Tobystihl]

Have a look at the spring on the choke flap, they weaken and the flap sucks closed on max revs!

 

[67L36Driver]

I’ve been transferring the spring from the OE air filter to the new (often aftermarket) filter for just that reason. The latest 026 being a case in point.

 

[HarleyT]

Does it make a difference if you turn it on it's side and shake it?

With a hooker, the difference would be about $100....

 

[CausticUC]

With a hooker, the difference would be about $100....

Hahahahaha

Does she tell you that you have a pressure issue too or is that extra?