I just rebuilt my first 039 stihl chainsaw.I put new fuel lines and fllter.Saw will not run unless you spray fuel in the carb.It fires up and runs out of fuel.I installed a new carb.Took one of an 029 and tried it.Same symptoms.The 029 saw was running great.help
stihl 039 rebuild
- Thread starter chris ham
- Start date
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Jerriod Raab
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cus_deluxe
Commie Satan turd
Yep, a pretty common thing on these, especially with aftermarket fuel lines.
cus_deluxe
Commie Satan turd
Also check the impulse line
It is an aftermarket fuel line.I just poured the gas out and checked it.It does not appear to be kinked.Would you replace it with oem.The impulse is oem.It appears to be hooked up on cylinder correct but the inspection window is very narrow.It will fire and run for a second every time you squirt a little gas in it.
Knobby57
Peeing outdoors
Check your impulse line is on...... woops I’m slow
Did you reuse the crank seals? Did you test for air leaks?
happysaws
Addicted to ArboristSite
happysaws
Addicted to ArboristSite
Is the intake boot cracked? That would cause some problems...
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Sent from my E6830 using Tapatalk
cus_deluxe
Commie Satan turd
It would have to be a massive air leak for it to keep the saw from even starting. Possible you rolled a lip on one of the seals. My moneys still on the fuel line. Those things take a hard 90 in the carb box, it may appear to be not kinked from the outside, but be closed off inside. Do you have any way of applying a few psi to the fuel tank to see if you can get fuel to come out the line?
captain dangers
partner 1633B (skil) chainsaw
well imo it doesn't sound ? like its getting fuel to the cylinder via the carburettor, this could be down to various reasons from a simple clogged fuel filter and dodgy fuel lines, to a clogged gauze screen in the carb, a stuck metering needle in the carb, and a carb kit not properly fitted? a porous impulse line could also be the problem, or an air leak? the carburettor relies on vacuum created by the piston going up and down the cylinder, so if the crankcase has a leak (usually seals) then obviously vacuum will not be created resulting in no fuel getting to the carb. it could possibly leak at the intake boot or if the carb isn't seated properly. I'm not familiar with this models pulse line bout if it has the type which passes through the intake boot then make sure its mating up properly to the pulse/vacuum orifice in the carb, the rubber intake boot should have a steel spacer/washer insert to enable the intake boot to keep shape under vacuum and to maintain a good seal to the carb.
you say you rebuilt it ? this is a broad brush , do you mean you stripped the engine and re-built that ? if so, did you us an oil compatible gasket sealer between the cylinder and sump/pan when putting it backtoether? as it could leak there ? Captain Dangerous
you say you rebuilt it ? this is a broad brush , do you mean you stripped the engine and re-built that ? if so, did you us an oil compatible gasket sealer between the cylinder and sump/pan when putting it backtoether? as it could leak there ? Captain Dangerous
cus_deluxe
Commie Satan turd
captain dangers
partner 1633B (skil) chainsaw
I completely disassembled the saw.I used permatex motoseal between the belly pan and cylinder.I did not apply any around the crank seals.I let it dry 24 hours.The carb boot looked good.It acts like it is getting zero gas.I took the fuel line lose and blowed am stumped air through it.It came out the tank filter.I tried an aftermarket new carb .This did not work.I then took one off an 029 that I ran 4 days ago same results.Fires right up when fuel is squirted in the carb then dies.For it to die that fast I would think it would take a massive air leak.
happysaws
Addicted to ArboristSite
What are the hi and lo speed screws on the carb currently set at?
captain dangers
partner 1633B (skil) chainsaw
for some reason it isn't pulling fuel so it will be for one of the reasons I mentioned earlier . I'm leaning towards a leak somewhere if the carb that worked days ago isn't working now. its sounding more like a vacuum problem I'm afraid, when I fit Stihl intake boots I smear a little grease around the seat to get a better seal. if your lucky its leaking their or the pulse line failing that you will need to pressure/vacuum test it as well as compression test it, as it may even have a hairline crack in the cylinder which fortunately isn't common, but isn't unheard of either. You could try using a gravity fed tank hooked up to your carb to see if it will run using gravity, if it runs with gravity but wont tick-over or has high revs that cannot be reduced via the L Jet, then it would suggest an air leak leaning the fuel out. C.D
