Chainsaw hard to pull

Most chain saws don't use "valves" but just have an exhaust port from the side when the piston is down. You MAY be just carboned up in the cylinder head so compression is too high causing extra hard force to go over the center. Maybe you are running with too much oil mix or there could be a failure of the con rod bearing.

I have a Homelite XL and was having problems with rope pulling from difficult to unable to pull rope while trying to start saw. I removed the muffler, squirted some WD40 through the exhaust port ABOVE and BELOW the piston compression ring. Then pulled the rope about 20 times without spark plug to fully lubricate the piston and cylinder. Left it till the next day, pulled it through about 20 more times, put the spark plug back in,and it works well now. Guess it was just gummed-up a little and the lubrication freed it.

If you have fuel to the plug and a spark at the plug it is going to fire, unless it has sheared the flywheel key and the timing is out, or it has scuffed the piston, it may seem to have some compression but that could be because the cylinder is flooded, just remove the muffler and check the condition of the piston through the exhaust port.

It could be a few things, completley flooded,starter pulley tight on its pivot post, the ignition unit too close to the flywheel and rubbing, or the egine has partly seized, remove the starter housing, with it off the saw does it pull freely? check the air gap between the coil and the flywheel, this should be 0.3mm, turn the flywheel by hand with the plug out, does it turn freely? if not remove the muffler and check the condition of the piston through the exhaust port.

Try some penetrating oil through the spark plug rotate the piston several times and re-apply the penetrant. Lean the saw sideways with the fuel side down and the exhaust side up, overnight.
Pull the start cord (the next morning) several times. Give the cylinder a quick shot of starting fluid and re-install the spark plug.
Should start!
Best regards, --W/D--

Short of building larger muscles in your arm or buying a model of saw that has a compression release, there doesn't seem to be much hope. Sorry about that!

It should be hard to pull during part of the revolution... this is the compression stroke and is normal.

Better chainsaws have a compression release that allows the engine to spin faster while cranking and then closes when it fires. These are easier to start but cost more.

Please do the following then reply below with what you find.
Starter Handle difficult to pull:
1. Was this saw perhaps operated in a lean condition (metal transfer from the piston to cylinder wall)? This may be caused by many things including but not limited to; leaky intake connections at the engine or carburetor; leaky crankcase seals; running on gasoline containing no 2-cycle oil.
· Remove the spark plug wire and plug. Remove the muffler, hold a light at the plug hole and inspect the cylinder through the exhaust port. Is it smooth and shiny or does it appear speckled with dull gray spots or smears?
· Pull the starter slowly, inspect the piston as it rises and falls. Is it a dull gray without scratches and gouges?
· Hold the light at the exhaust port and look through the spark plug hole, inspect the cylinder above the exhaust port. Is it shiny and smooth or speckled with gray spots or smears?
Any spots or smears on the cylinder or deep scratches and gouges in the piston indicate the saw was operated in a lean condition. Repair of this on a home owner quality saw often exceeds replacement cost. A repair estimate by an independent saw shop should be considered.
2. The last likely possibility is the saw has jumped timing. This problem or any not discussed is usually beyond the ability of the operator to repair. Please take it to a good local saw seller/mechanic for a written diagnosis before authorizing any repair. HTH
Lou

If the plug is wet the saw is flooded. Try the following to clear that condition.
Extreme Flooding by Dolfoff; Please follow this link,
http://www.fixya.com/support/t3226410
cursor down to “Best Solution”, while there click the “Was this helpful? [Yes]” button.

Once the flooding condition is cleared this start procedure works for every saw I have (7). Please read line 3 twice; both cold and warm.
Start Procedure
Cold:

1. Ignition on/off to on
2. Set compression release – optional step even if saw is equipped with a compression release
3. Pull (close) choke, set fast idle (done when choke closed on some saws); pull starter and listen for an attempt to start. once heard (usually two pulls; no more than 4)
4. Set compression release – optional step even if saw is equipped with a compression release
5. Push (open) choke pull starter until it starts. (usually first pull)

Warm:

1. Ignition on/off to on
2. Set compression release – optional step even if saw is equipped with a compression release
3. Pull (close) choke, set fast idle (done when choke closed on some saws) – Do not pull with choke closed.
4. Push (open) choke, pull starter until it starts. (usually first pull)

Good Luck. HTH
Lou

It’s possible the ignition module has gone bad do this first. If it’s good and the saw will start it may quit when it gets hot. I don’t think that is true but keep it mind. If it does suddenly just quit running, immediately test the coil before it can cool.
Ignition Coil Test
SmallEng.com
http://www.youtube.com/watch?v=L7WNBDRG4C4
You may need to use a jumper wire between the threaded part of the plug and the cooling fins. You don’t have to bend up the electrode.

You refueled it and it wouldn’t start? Any chance you put straight gas in it?
Was this saw perhaps operated without oil mixed with the fuel?
· Remove the spark plug wire and plug.
· Remove the muffler, hold a light at the plug hole and inspect the cylinder through the exhaust port. Is it smooth and shiny or does it appear speckled with dull gray spots or smears?
· Pull the starter slowly, inspect the piston as it rises and falls. Is it a dull gray without scratches and gouges?
· Hold the light at the exhaust port and inspect the cylinder, above the exhaust port, through the spark plug hole. Is it shiny and smooth or speckled with gray spots or smears?
Any spots or smears on the cylinder or deep scratches and gouges in the piston indicate the saw was operated in a lean condition. Repair of this on a home owner quality saw often exceeds replacement cost. A repair estimate by the independent saw shop should be considered.

It might be a bad fuel vent? Not likely if you just refueled, more likely if it staves after running for a few minutes. Loosen fuel cap when it starts to sputter (rotate saw if necessary) if it picks up again bad vent.

Most likely it was flooded. A flooded saw can be extremely difficult to restart. Did you try to choke a hot saw? That is almost guaranteed to cause it to flood.
Start Procedure
Cold:

1. Ignition on/off to on
2. Set compression release – optional step even if saw is equipped with a compression release
3. Pull (close) choke, set fast idle (done when choke closed on some saws); pull starter and listen for an attempt to start. once heard (usually two pulls, if not heard after 6 pulls stop! Something is wrong)
4. Set compression release – optional step even if saw is equipped with a compression release
5. Push (open) choke pull starter until it starts. (usually first pull)

Warm:

1. Ignition on/off to on
2. Set compression release – optional step even if saw is equipped with a compression release
3. Pull (close) choke, set fast idle (done when choke closed on some saws) - Don’t pull with choke closed.
4. Push (open) choke, pull starter until it starts. (usually first pull)

Hope this helps
Lou
If it was flooded it should start easily if it has been sitting for a couple of days. It could still be coil or vent problem.