Sthil 034/036 Kicks like a mule when trying to start.

[Johndrew98]

I have a Stihl 034 or 036 . The S/N is 114994544 but no one can tell me what it is. It has 036 on the starting rope mechanism and 034 AV on the top cover. I looked up the part number on the brake and it shows 034 or 036. Fits both. It ran good yesterday but had a problem getting it started. The compression was like a mule kick after about 6" pull . I took out the spark plug and put Seafoam in the sparkplug hole and pull a few times with the plug out. Pulled easy and tried again and started and cut up a tree. Today it's the mule kick again Only turns about one stroke of the piston When I pull the sparkplug it pulls easy. The chain brake is off and the chain runs smoothly on the bar. I took off the muffler and the piston side looks very smooth...except there is a film on top of the cylinder about the thicknss of a piece of paper. I can lift it with a pencil about 1/8 high as far as I tried. Appears to cover the entire cylinder head. The top of Piston from the carburetor side shows some carbon build up. (not shinny but has an even carbon look) Question first does anyone know which saw it is from the S/N?. 2. How do I get it to pull without the mule kick? I don't see any decompression valve. If you think the issue is the carbon on the cylinder, is there an easy way to remove. Could it be the spark plug or gap?

 

[Brushwacker]

Timing maybe? Spark plug gap is .020, wider can cause issues.
034 super and 036 are little if any different . 034 is a smaller bore all else the same as the super.

 

[northwest saws]

034 or 036, both are getting up there in years and if its seen some good use you can bet there is some decent carbon buildup. That film is either from excess oil in the mix or the sea foam got some of that carbon buildup loosened up and you're looking at a layer of carbon soup. From what you're describing it does sound like excessive compression from piston/ring failure or carbon buildup. However, there are a couple simple things you can check before addressing the cylinder. First check the flywheel to coil gap, too tight of a gap can cause the symptoms you're describing. The gap needs to be anywhere from .20 to .30mm. I would be skeptical of the timing being off but it would be good to check the flywheel nut and make sure its nice and tight and that there is no damage to the flywheel key or groove. If all those check out then check the clutch and drum for any kind of bind, sometimes excessive gunk or a foreign object can cause some resistance on the clutch and drum making it harder to start. If after that you haven't made any headway then it would be best to pull the cylinder. I wouldn't try cleaning out that crud with the cylinder on. There's also the chance the excess carbon buildup is being caused from a piston fault. It would help if we could see some pics! I cant really say with absolute certainty but from the serial number it sounds like you have an 034.

 

[Mad Professor]

Is this only after sitting and cold?

Maybe it gets flooded full of mix. Mix won't compress well........

 

[67L36Driver]

A cold lean mix will kick back.

Mostly on hard kickers (Homelite XP-1000) I leave the switch off, set the choke and give it a couple pulls. Turn on the switch, set half choke and pull it like it owes you money.

A rich mix has a slower flame speed and the extra fuel limits peak temperature/pressure.

 

[TRTermite]

Doesn't the 036 have a decompression? But the 034S doesn't?

 

[cuinrearview]

Doesn't the 036 have a decompression? But the 034S doesn't?

No. Best way to tell(if nothing has been altered) is the location of the chain tensioner. The fin arrangement on the top of the cylinders is different too.

 

[TRTermite]

No. Best way to tell(if nothing has been altered) is the location of the chain tensioner. The fin arrangement on the top of the cylinders is different too.

Thanks for the clarification

 

[Brushwacker]

No. Best way to tell(if nothing has been altered) is the location of the chain tensioner. The fin arrangement on the top of the cylinders is different too.

I only remember 1 034 with the tensioner screw in front. I have and ran many 034 and 034 super s with side tensioners.

 

[cuinrearview]

I only remember 1 034 with the tensioner screw in front. I have and ran many 034 and 034 super s with side tensioners.

Supers yes. The other ones were likely fiddled with.

 

[Brushwacker]

Used to work at a new stihl dealer ,1989-90, thought all that went through were side tensioners.