Stihl 034 Super not getting fuel

[CrespyCream]

Hi everyone first post here, wish it was under better circumstances! I recently acquired a 034 super and i’m at my wits end with it. The dang thing just will not run no matter what I try and I feel that i’ve exhausted my options I know of.

For starters the thing looks great, fresh rubber all the way around (OEM) so no air leak that I could find. I’ve verified strong spark with a new plug, threw a new fuel line, filter, tank vent, and 2 different carburetors at it and still no luck. Piston looks great too, no scoring or concerning marks visible on intake or exhaust side.

I’m very suspicious that it’s simply not getting enough fuel. The impulse line is not cracked but i’m wondering if the fitting might be gunked up? I tried getting a small wire in there and pressing around but still no luck. Anyways the carb does have fuel in it if i take it apart but I did notice that if i remove the fuel line to the carb no fuel comes shooting out like all my other saws do. However if i unscrew the cap, blow in it then reseal the cap fuel will come spraying out of the line.

If i try and start it for a while then remove the plug, it is very slightly moist not soaking wet like a flooded saw would be. I’m very comfortable tuning my saws, and messing with that has also not worked. However if i pour a little fuel in the cylinder it will want to fire up right away with only a pull or two. I really am thinking it’s just not getting enough fuel inside the cylinder but I am absolutely stumped on why that is!

 

[Canadian farm boy]

How’s the compression?
Is the choke closing fully? The little plastic tab on the control lever rod and the hole the control rod that goes into on the clutch side of the carb box tend to wear and get sloppy.
Set your H and L screws at 1 full turn out from seated for a starting point and tune them from there.
Is the idle screw backed out too far and the throttle blade totally closed off?

 

[bogieboy]

Make sure the choke is closing ALL the way... the 034 had one of the worst chokes on it that would only go 3/4 if stuff got a bit sticky...

You can pull the air filter off, and hold your thumb over the carb inlet to prime the carb as well, that way you know its choking...LOL if it teuly isnt getting duel, your thumb will remain dry, if its a choke issue, your thumb will be wet with mix in about 2-3 pulls of the rope...

 

[bogieboy]

Also, by fresh rubber, does that include crank seals? Or just fuel/impulse/intake? Could have a bad crankcase seal drawing air and negating the pulse signal

 

[drf256]

I’d pressure test the saw though the impulse line. That saw used a regular piece of Stihl tubing connected to case nipple and a 90* plastic fitting cast into the tank. Check the area where the boot seals to the tank and the carb as well. Boot should have inside and outside metal rings installed, but no gasket.

I’d try a third carb as dumb as that sounds. Also, test the fuel line and the filter, I’ve had those be bad as well. Best to drill the tank and use the newer S shaped 036 line.

Pull the flywheel and make sure the key isn’t sheared. Won’t take much work and can drive you crazy if it’s sheared.

My own 036 won’t choke and run without a shot down the carb bore. They all have an awful choke setup. I have the coveted HK43b on mine, and the same thing loses prime easily. My carb is NOS, yet the saw runs better with a cheap eBay China carb.

 

[Coupe]

If you did a carby rebuild and you have the carby diaphragm has a slot in it and
a slot in the needle valve make sure you have married them togeather.
If not the needle will be fully closed so you will not be getting any petrol.
Also if you have a pressure tester check chrank seals are all okay. Also try
it with the fuel cap open a few turns as when you take the fuel line off the
carby usually you cannot stop it running out that sounds a bit suspicious
to me also.