Monday, September 17, 2012

Starter assembly service on Stihl Easy2Start chainsaw

Linda uses a 2012 Stihl MS180C-BE saw. This saw has the two-stage starter spring that makes it easy to start, thus the name "Easy2Start" indicated by the "E" model letters. The internal differences become clear when you break a starter rope, as I did this morning. I took the opportunity to see what the innards look like and to clean out the cooling fan and spring housing.

The Stihl Easy2Start saws like our MS 180C have thin pull ropes. If you have one of these saws, here are step-by-step instructions for how to replace the starting rope.

The Stihl MS180C is a super lightweight 32cc saw that's excellent for limbing, topping and bucking up to about 8 inch diameter logs. The chain adjuster is toolless and the tank caps actually stay on every time. The small chain dulls easily but is correspondingly quick to resharpen; also cheap enough to keep a sharp spare chain.

The Easy2Start option is a nice feature for sawyers with wrist injuries or who simply don't have the arm strength to start a cold saw safely. There's no resistance on the rope until it reaches its full extent, then all the coiled-up pull is quickly released to spin the engine.

Don't think of it as a broken pull rope, think of it as an opportunity to see how Easy2Start works.


How to replace the starter pull rope


You'll need a new rope, which is a smaller-diameter nylon rope than typically found on saws. You'll also need a Torx 25 driver. A 6 inch strand of copper wire is handy here, or you can get by with narrow needle nose pliers and the wire hook you use for fishing out fuel filters. A small piece of wood will come into play and I expect you can find plenty of those laying around when the time comes.

Remove the shroud like you do to clean the air filter. Lay the saw where you can work on it. The starter assembly is on the side with the fuel cap, where the pull handle should be, opposite the clutch. Remove 5 screws that secure the starter assembly.  Use the right tool for this, a Torx 6-point driver, either the driver type or on a ratchet, not a screwdriver.

Remove the shroud (previous photo), fuel, oil, and cap retainers, then remove the starter assembly.
One of these 5 screws is not like the others, so remember where it goes (in the hand guard). Note also how the screws are not very tight. They thread into plastic. Set the screws aside.

Prudent precautions at this point would include draining at least the fuel tank. Leave the caps off both tanks. Take out their retainers with your hook and set the caps aside.

Gently stretch the hand guard upward enough to pull the starter assembly off the saw body.

STOP HERE for a moment and take a look around this unusual starter...

First, if there's any rope left on the pulley, notice which direction it is wrapped, but leave it there for now.

Starter assembly from the inside.
Next, see how the white nylon dogs are spring-loaded by the small wire clip? With centrifugal force they extend outward and catch the lugs on the interior of the aluminum fan hub. But until the accumulated force is released (at the end of your pull) there's no contact. That's why it's easy to pull. In fact, if you pull too hard you break the rope, which is why we're both here instead of outside working.

Now clean out any oily sawdust and dirt that has accumulated inside this housing and on the aluminum fan. Just gently brush it away and wipe it up with a rag, use compressed air if you have it, but don't go overboard by using liquid cleaners. 

Carefully remove the wire clip holding the white plastic hub on the shaft. You might want to print my photo or take your own, so you can be sure to reinstall the clip correctly. It must be right side up because, as you just saw, it does more than hold the dogs in place. 

Memorize the correct clip position, like the letter "N." Then remove the wire clip, NOT the 3 screws.
Lift the white plastic hub out, then remove the steel spring assembly. Keep all washers in order. You should not disassemble the spring itself unless you have a real good reason (e.g., it's broken) or the IFPL is on general shutdown and you're really bored and don't need the saw any time soon. If you do, see the comments section for help.

Now you can clearly see the entire rope pulley, which can stay where it is in the housing. I didn't get a photo of it, but it's pretty straightforward. Remove any remnants of the broken rope from the pulley. If no rope remains in the pulley, then locate a small depression where the knot will go, and a tiny hole from there out through the pulley. Also remove the rope piece from the pull handle.

Start re-stringing at the pulley end of the new rope. Align the hole in the pulley with the hole in the housing. With or without the help of some fine wire, feed the rope inward through the exit hole and into the pulley hole. From there pull the rope up through the depression and tie a good single knot.

Wind the rope going clockwise onto the pulley. If you're not sure you have enough rope on the pulley, temporarily attach the pull handle and have the saw's regular user give it a pull. If it's too short, the accumulated force won't release to start the saw.Correct that by wrapping more rope onto the pulley.

Then position the pull handle and eyeball how much rope you'll need to make a knot and finish the job. Cut and scald the rope end. Pull it out one pulley revolution and block it with a small piece of wood. Insert the rope into the pull handle and tie a good double knot. Release the block and test the fit. The handle should snug up into the housing, not flop around.

Reassemble the pieces in order. Careful when you tighten the Torx screws, you don't want to strip out the plastic threads. Refill the fuel and oil. Replace the tank caps and shroud, flip the hand guard back, and reset the start-stop switch. Test start the saw. Congratulations. Now get back to work. 


  1. What length pull cord do you need for this model? I have to replace mine. Thanks!

  2. Thanks for the info on replacing the starter cord. I would recommend that you add another precaution in your description, about not messing with the spring. The white hub did not come off easily on my machine, and I pulled the pulley up enough to dislodge the spring. I had no idea that there was a spring on the other side of the pulley. Took me about 2 hours to make a tool to rewind the spring to the point where I could install it, and get things back together.

    The tool that I made was a bottle cap with an ID a bit smaller than the spring max in the saw, and cut out slots for the loop to stick out, and for a needle nose vice grip to grab the spring coiled into the top. I was able to lift the spring out with the vice grips about 90 degrees from the loop, and gently lay it into the housing. I first put the loop into place and then holding the spring into the housing with all available fingers release the vice grips and let the spring take its place in the housing.

  3. John, sounds like you devised a clever tool to get you through that ordeal. I hope never to disassemble that spring, but if I do I'll surely refer back to your description. I added another note to stop readers short of repeating your experience.

    As for the length of the cord, Jonathan, I installed a generic pull rope, then cut it to length. It has to be long enough to release the accumulated force of the pull. You could guess it by laying the broken pieces end to end (if you didn't throw part of it halfway across the woods when it broke) but it's easier to just assemble everything as described above, test the feel, adjust, then cut the rope after finally reattaching the handle where you want it.

  4. I read the warning about dislodging the recoil spring, and my heart sank when it went flying. My remedy for getting it back in place was to carefully recoil the spring with my fingers, then have a friend use three nylon cable (zip) ties to hold it together. After positioning it back in the housing, I cut and removed the cable ties. Took all of 15 minutes.

  5. I have a MS180c easy start that the pull cord snapped I put it all back together and works as it should while off the saw but when I put it back on the saw and go to pull it and it’s not catching on the fly wheel. What could be the problem. Any advice would be greatly appreciated Thanks


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