Rope Pulled Before Kill Switch

[JoeMay]

I’ve seen operators pull the starter rope out a bit and hold it just before activating the kill switch. This is seen mostly with operators running older saws. I would guess it is a precautionary action to protect the recoil starter mechanism. If so, I appreciate some details and specifics. I have several older saws that run well and want to keep them running well.

 

[ballisticdoughnut]

It depends on the type of engagement mechanism in the recoil starter. As the engine winds down to a stop it can rotate counterclockwise as it slowly spins up on the compression stroke. Almost like a spring is forcing the engine to rotate in reverse. If the pawls are on the flywheel they will catch on the rope pulley and stress the rope. Starters that have pawls in the rope pulley don’t have this problem. Holding the rope out before stopping the engine is just a way to reduce that shock to the recoil. If you hear a clicking sound as the rope is retracted (pawls on flywheel) you’ve got the “ratchet” style mechanism. These are the saws that will catch as the engine comes to a stop. No click sound the pawls are on the rope pulley and there’s no need to pull the rope out before stopping the engine. I’m not always the best at explaining things so hopefully that makes sense.

 

[JoeMay]

It depends on the type of engagement mechanism in the recoil starter. As the engine winds down to a stop it can rotate counterclockwise as it slowly spins up on the compression stroke. Almost like a spring is forcing the engine to rotate in reverse. If the pawls are on the flywheel they will catch on the rope pulley and stress the rope. Starters that have pawls in the rope pulley don’t have this problem. Holding the rope out before stopping the engine is just a way to reduce that shock to the recoil. If you hear a clicking sound as the rope is retracted (pawls on flywheel) you’ve got the “ratchet” style mechanism. These are the saws that will catch as the engine comes to a stop. No click sound the pawls are on the rope pulley and there’s no need to pull the rope out before stopping the engine. I’m not always the best at explaining things so hopefully that makes sense.

Thank you for the excellent answer and useful information. Checking for clicking vs not clicking during rope reel-in will save me from taking the starters off all my saws to see the location of the pawls.

 

[KRP]

Now is the time to take all of the starters off your saws.... for inspection and cleaning, of course.

 

[JoeMay]

I actually did just that during this long grueling winter, which today just dropped several more inches of heavy, wet snow. Set a new record in Duluth, over 135 inches. Unfortunately, I did not take special note of the pawl locations when I had the recoil starters off. I’ve got a pretty good memory of the various saws pawl locations. Click vs no click will quickly provide verification.

 

[Seachaser]

I saw a video of a guy stopping his saws like that. Never saw it before. And these were new saws.

 

[Pudsy]

I saw a video of a guy stopping his saws like that. Never saw it before. And these were new saws.

Consider it good practice, just to be sure. If you operate a lot of 'unknown' (to you) saws it doesn't hurt to do this even on saws that don't need it. It's a bit like operating your direction indicators in your car, even when there is no one around for miles - just good habit to it always, so you don't forget when it is actually needed.

 

[heimannm]

If the starter pawls are in the starter itself, you run the risk of them catching on the starter cup if you pull the rope while the saw is running.

Mark

 

[Pudsy]

Hmmm, you may have a point there, but on the mechanisms I know, if the engine is spinning faster than the starter, the notches on the starter cup would just press the pawls back in (much like the pawls in a ratchet on the "back" stroke). It will make a rattling noise (like a ratchet), but I don't see the pawls "catching" and causing damage. Or are there mechanisms around that have some form of non-sloped catch?

 

[heimannm]

When the parts start rattling around at 3,600 RPM there is no way to predict what might happen.

Mark

 

[Bill G]

When the parts start rattling around at 3,600 RPM there is no way to predict what might happen.

Mark

It is even worse when they go flying at 9000rpm.

 

[Pudsy]

Just out of interest: Is this hypothetically/theoretically or have you actually had this happen on some saws (which?)?
We're taking gently pulling (not yanking) the starter rope out an inch or two while flicking the stop switch from idle speed, right? I've never had this procedure cause pawls engaging or hitting anything. Then again, I only have some 200+ chainsaws, amounting to maybe 100 different models, so there's bound to be plenty I've never seen/experienced yet ...

 

[Chevboy0167]

 

[huskihl]

There are saws that you should do it on just like Mr doughnut said, and some that you should never do it on, like Mark mentioned. Stihls since at least the 028 era have pawls in the recoil and pulling the rope out actually forces the flywheel to catch them if it reverses once it stops. So don’t do it on a post-80’s Stihl

 

[Pudsy]

pulling the rope out actually forces the flywheel to catch them if it reverses once it stops. So don’t do it on a post-80’s Stihl

Well, catching (if that happens) when the engine reverses is what the pulling is intended to mitigate by providing some rope to be pulled back in, so I don't see any damage coming from that, but you're right of course that it is not necessary on these saws, so might as well leave it be.

The problem is of course what to do when shutting off a saw that you don't know the innards of. My take has been that giving the rope those two inches of leeway doesn't hurt the saw when it is not needed, whereas not doing it on a saw that does need it may well result in extra strain or even damage.

I may well be wrong on that, but this is how I have been handling it. Mark addresses the pawls hitting/touching the drum while spinning down from idle to stop (not on the back stroke of the last incomlete compression) and I have never had that happen to me, so please tell me if this is a regular thing on certain saws. Happy to learn of course.

So what is your practical solution to this discussion? This being basically the question of the OP: What do I do when I wish to shut off a saw that I don't know the mechanical details about?
To pull or not to pull? Or just leave the saw running forever ;o)

 

[Chevboy0167]

So... has anybody actually read in their saw manual the pull before kill procedure? Ya know, cuz we all have and read em... LOL
Curious to this as it may really say it for some older vintage saws....

 

[Pudsy]

So... has anybody actually read in their saw manual the pull before kill procedure?

The video you posted actually goes into that and shows this for some old McCulloch manuals ;o)

 

[Chevboy0167]

Yes, just wondering if anybody on this site remembers it. The only vintage saw manual I have is for Shindy 488 I think... and have not read through it with great detail.

In fact, it is the only saw manual I have! LOL Even my brand new never had fuel in tank 562XP from the original owner never had the manual.

 

[huskihl]

Most newer saws have lighter flywheels and the reversing from the last compression stroke isn’t as severe as it once was. I’ve never done it on a 394/5 and don’t believe I’ve ever replaced a pawl on one. The rest of the 395 carcasses I have are in considerable various states of disrepair but the fw pawls are still good

 

[Tony Mayhew]

I own at least 70 vintage chainsaws and have had this happen to me once back when I was still a rookie and didn't know about them kicking back! Homelite XL-101 I forgot to pull the rope before hitting the kill switch and it popped the handle off the rope and ruined the rubber handle! Hard lesson learned.