stihl 056 av

[savitout541]

I recently bought a stihl 056 av it runs and idles good but when I pull the throttle it bogs down and just won't hit the high rpms
I checked the adjustment screws on the carb and the high was set just half a turn out so I turned it out 1 and a quarter turn but it still does the same thing I checked the carb the diaphrams they seem in good shape
Also yesterday I tried starting it and it flooded and gas came out of the muffler
But it did start but still won't rev up

 

[Rivets]

I would try leaning the mixture out, set ay 3/4 out from lightly seated. It may be running to rich. Did you buy it new?

 

[savitout541]

No I bought it used

 

[Rivets]

If leaning the carb out does not work, you'll have to look for an air leak and/or rebuild the carb.

 

[savitout541]

I just ordered a leak down tester from cornwell so if rebuilding the carb doesn't work ill try a leak down test what do I have to do to do a leak down test on it ?

 

[Rivets]

A leak down test on these small 2 cycle engines is not easy. You need to bring the piston to TDC and hold it there. Apply air pressure into the cylinder and listen for any leaks. The piston cannot move while doing this. What you will be trying to find is if any air is leaking passed the rings.

 

[savitout541]

What are some ways of holding the piston at TDC ?

 

[Eugbug]

Check the air filter to make sure it isn't restricting the airflow and also fuel filter.
Blow out jets on carburettor.
Check vent on tank and look for cracked fuel lines.

 

[Rivets]

That's one of the reasons it is difficult to test. I normally remove the cover and wedge the flywheel so it cannot move. There may be some U-tube videos that would help, but I never go there.

 

[mullins87]

I have an 041AV, but other than a carb rebuild, I haven't had to do much to it. Is there a spark arrestor screen in the muffler? Every other piece of 2 stroke equipment I have has one, and when they get clogged up, they will run exactly as you describe.