Stihl 044

[jstoshick]

Pulling my hair out on a refresh of a stihl 044; I had the saw gifted to me with it being hard to start. It wasn't run for a long time; I replaced a clutch spring that was not allowing the clutch to disengage which I figured was probably the hard start condition it previously experienced. I renewed all the rubber and it ran ok for a short time. Following actions taken:

-New carb & went back and got a zama rebuild kit thinking it was a cheap carb.
-New impulse line, intake boot, and fuel line / filter. All seem to fit well.
-New coil (tried old coil) & a million little adjustments. Spark is good.
-Compression around 110psi
-A zillion adjustments to try and cut off fuel – needle, screws, etc. Carb is super clean; lots of previous experience rebuilding so believe this isn't where the issue rests.

Condition: Saw is hard to start and won't rev unless I remove the impulse line. With line connected, it floods and spits fuel back. With the line removed, it revs and idles, but somewhat erradic.  Checked to ensure clear line & clear into crankcase. Almost acting like it has the start of a cracked piston or bad rings – something that might introduce excess pressure to the crankcase? – but the compression test indicates good. Any ideas? What am I overlooking? I am pulling my hair out!!! Cheers!!!

[joe_indi]

..........New carb & went back and got a zama rebuild kit


Condition: Saw is hard to start and won't rev unless I remove the impulse line. With line connected, it floods and spits fuel back. With the line removed, it revs and idles, but somewhat erradic.

I never knew the 044 had a Zama carb. I have only see Walbros on them

When you put in the rebuild kit, how have you positioned the pump diaphragm and its gasket?

With carb placed with pump side facing up it is the diaphragm, then the gasket and finally the end cover.
The flooding and spitting of fuel when the impulse hose is connected usually is a symptom of a damaged pump diaphragm.
However, with you having replaced the diaphragms and gaskets (rebuild Kit), the possibility is that the the gasket and diaphragm are placed incorrectly.
The only other possibility that comes to mind is if you have used a Zama kit on a Walbro carb

[jstoshick]

Its definitely a zama carb (the original one I got with the saw at least -- the replacement was a no-name). 

You have me thinking on the gasket placement; I just rebuilt a husky 394 and the diaphram went above the gasket. IE: Carb, gasket, and diaphram. I might have made a mistake here and carried that over that from the Husky rebuild. (I put the husky back together from pieces and it did not run with the config of diaphram, gasket, cover -- which is why this was engrained.  I will try this tonight. Thank you very much!! :-)

[jstoshick]

Not paying attention close enough to the part names:

I did have the pump side together properly: Carb, pump diaphram, gasket, cover. 

Metering value side: Carb, gasket, diaphram, cover. (This is the side I had to fool with the other saw noted). 

[joe_indi]

On extremely rare occasions, on the cylinder, the  cylinder wall on the inlet side could get badly worn, usually a little above and a little below the inlet port. Such saws will indicate satisfactory compression, but tend to have extra strong (dont know a better way to describe it) impulses . Such saws could have a similar issue to that you are facing.
The only way to check is by lifting the cylinder.
However, before taking that step, try another carb. Even one from a 460 or 361/360 will do. You dont need to connect the throttle linkage or have the choke working, or are the filter bases required. Just tighten down the carb with the fuel hose fitted. Turn in the idle screw a couple of turns. Squirt some fuel into the carb and pull away. That engine has to fire up. Use a finger or screw driver to try revving. If you see the same symptom even whith the test carb, go ahead and lift that cylinder.