Stihl 064av dies when trottle released

[mantas]

Starts great, idle great, but dies out as soon as the throttle is released and then it needs 2-3 pulls to start again but need to hold the throttle lever, and this happens only when its under load while cutting, non loaded runs good it doesnt die.
Normally i`ve tried to re-tune the carb several times, also i`ve cleaned it and still doesnt work.
What to do?

 

[ZeroJunk]

When it is running good with no load is the chain spinning ?

 

[Scooterbum]

You have a crank seal getting ready to go.

 

[sefh3]

Vac test the saw. Look closely at the flywheel side seal. It sounds like your sucking air.

 

[Husqavarna Guy]

I also have been working on a 064. Is was easy to get running now takes a lot of pulls to start. It feels like it has lots of compression and piston looks brand new. Anybody have any ideas?

 

[dswensen]

I also have been working on a 064. Is was easy to get running now takes a lot of pulls to start. It feels like it has lots of compression and piston looks brand new. Anybody have any ideas?

It COULD be fuel or fuel delivery. Has it been setting for a while? Did it sit with fuel in it? Does it have fresh fuel?

 

[mantas]

When it is running good with no load is the chain spinning ?

After cold start it spins until gets warm, then the rpm falls and the chain doesnt spin
as it gets hotter the idle rpm`s decrease

 

[Scooterbum]

Trying running it turned sideways in either direction and see if that has an effect.

 

[ZeroJunk]

If I am reading the OP correctly the saw operates properly when there is no load on it. So, I don't see what difference that would make unless the clutch springs are weak and it is trying to turn the chain at idle.

 

[Big_Wood]

I once had this problem on a stihl 064. Figured it out in minutes. Was a cracked intake. Intalled a new one and she ran good. I believe it still runs today. That was going on 10 years ago now but my old neighbour still has it and uses it for firewood

 

[Fish]

Go back into the carb, correctly.....

Install a new kit with needle, and set the height correctly, first.

 

[mantas]

Yup, i`ve found this http://www.wind-drifter.com/technical/walbro_chart.jpg"] and it seems the diaphragm is bad, if not im going vacuum test the saw

 

[blsnelling]

An air leak will cause it to idle too high, not die.

 

[indiansprings]

Had a 034 super on the bench today same symptoms, ran the carb thru the ultra sonic,put a kit in it, painted the welch plug with high quality finger nail polish just for insurance, let it dry, put it back together and it ran and idled like a new one

 

[Scooterbum]

Had an 024 Super do that exact same thing. Did the carb and fuel line thing and no fix.

Turned out the bearings were shot. New bearings and seals and runs like a top.

Sucking way too much air will make them stuble and die when returning to idle.Seems the bearings under load were opening up the seals too far.

Also remember a poulan 330 that had the same problem but they had a carb swap for it.Can't remember exactly what the issue was, maybe someone here can.

 

[mantas]

Go back into the carb, correctly.....

Install a new kit with needle, and set the height correctly, first.

The metering-needle lever should be level with the surface of the carb, right? it wj6a carb