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041 AV Extremely hard to pull

Started by Rick237, November 11, 2015, 09:35:12 PM

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kenskip1

One way to tell if it is a timing issue that is foolproof. Ready for it? Try and start it with the ignition switch OFF.If it is a timing issue this will tell you in an instant or better yet even unplug the wire from the spark plug. Either way this will tell us what we are looking for.With the switch in the off position no spark so no timing issues.I am going out on a limb and say you have a carburetor problem. It is leaking gas down into the cylinder and this is causing your hard pulling. Remember that gas and oil will not compress. You are fighting what is called hydra lock or something of this nature. I hope this helps you, Ken
Stihl The One
Stihl Going Strong
Stihl Looking For The Fountain of Middle Age

Rick237

Thanks Ken -- I am sure that it is not a leaking carb because I often remove the spark plug, inspect it, and look inside. I would notice any wetness. And, before I installed a fuel primer, it took a good seven or eight pulls to get any fuel into the cylinder in order to get the first pop. I have also pulled the cord many times with the ignition grounded to see if it was still hard to pull and it is the same except when, with the ignition on, it kicks back and pulls my arm back down which now happens more often than not. As you probably know, ignition starts before top dead center in order develop full force at about 90 degrees after TDC in order to apply the maximum force or torque to turn the crank shaft. At the very, very low rpm when pulling the cord, more force develops before TDC which can snap your arm back down. That kick back can be eliminated or lessened be igniting the fuel later in the cycle or closer to TDC or right at TDC. That is what I meant by retarding the timing. The problem with retarding the timing would be less power at high rpm because the maximum force would be taking place after 90 degrees. A well-designed ignition system would not kick back because the timing would be very retarded or very close to TDC at very low rpm and very advanced at high RPM. My ignition is definitly too far advanced at the very low starting RPM because it keeps kicking back. Harder to pull means a lower RPM which requires a later or more retarded ignition in order to prevent kick backs. My guess is that newer saws have better ignition timing graphs which eliminate most or all kick backs and still give maximum power at high RPM. Please forgive me if you knew all of this. I have been working on my pulling technique in order to increase RPM when starting and have made some progress. --Rick

kenskip1

Rick, from your post that you installed a primer bulb is proof that the gas is going into the cylinder. A 041 was not designed for a primer bulb. I am trying to help you. My 041 sitting in my garage will take 3-5 pulls to fire it up.Listen to what I am trying to tell you.The gas may not be leaking into the cylinder but into the crankcase. Eventually it gets drawn into the cylinder and this is causing your hard to pull anomalies. I am 60 and have been working on saws for close to 35 years.After the saw has been running a bit and you shut it off, a small amount of heat may be causing the gas inside the carburetor to expand. It is going down inside the engine.Into the crankcase or cylinder depending where the piston is.You need a carburetor kit.Best of luck, Ken
Stihl The One
Stihl Going Strong
Stihl Looking For The Fountain of Middle Age

beenthere

south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Rick237

Thanks Ken -- You certainly could be right because you definitly know a lot more about saws than me. A carb kit would be worth a try. It can't hurt anything and does not sound like a difficult job, especially considering the fact that I have the diagram and all the specs. And, I can take it inside and do it in comfort on my kitchen table. Finding the kit will probably be the hardest part of the job. P.S. I don't have a primer bulb. I just squirt a little fuel through a hole that I drilled on the top of the air filter cover. When I squirt it, I get a pop on the first pull which, unfortunately, kicks backwards and pulls my arm back down. For the first thirty years of my saw's life when it was much easier to pull, it took seven or eight pulls to get the first pop. Thanks again for your patience.

kenskip1

Stihl The One
Stihl Going Strong
Stihl Looking For The Fountain of Middle Age

Rick237

Thanks Ken -- Great link. I just ordered it and it is only $13 shipped. which was a pleasant surprise. 

Rick237

I invented a starting technique which works great for me. I am now able to start my saw with the first or second pull after priming and am able to get a full pull with two compressions. I have started it once or twice per day for the past week without the cord kicking back once and getting my fist slammed.

It is similar to the drop start except that I throw the saw to the left parallel to the ground instead of dropping it down. I stand with my feet about two feet apart or more. Hold the saw handle with left hand at stomach height with left elbow bent and bar pointing about 45 degrees to the left. I then twist my body to the right without moving my feet until the saw is completely to the right of my body and bar is pointing about 30 degrees to the right of straight ahead. I then quickly rotate back to the left while simultaneously straightening my left arm to get the saw moving faster. About half way through the rotation, I pull the cord to the right. For me, it works much better than the drop, back of the knee, or ground start where I get back fires and am not able to get a full pull or a fast pull.  It feels great that I can now start my saw without struggling for fifteen minutes or more.  Thanks again to all.

JohnG28

I don't know what the hell you just described, but I'm pretty sure I wouldn't ever do that to start a saw.  The first place I'd think to look is inside the starter housing. If there is an issue as pointed out with the rope or pulley that could cause binding you could also put stress on the flywheel, particularly if it was getting uneven pressure on different sides. I'd check for signs of anything like this. Check flywheel for a sheared key also if timing is off and kicking back on startup.
Stihl MS361, 460 & 200T, Jonsered 490, Jonsereds 90, Husky 350 & 142, Homelite XL and Super XL

Rick237

Thanks John -- I am going to remove the starter housing for a look. And I ordered a carb kit. In the last ten years, I have only started it four or five times for some light yard triming and it has gotten very hard to pull so I can only pull it slowly through one compression. Before that I used it to cut firewood logs that were delivered to my home and was always able to start it for three decades using both ground and drop start. Those methods no longer work so I tried something different. By throwing it to the left and pulling to the right, I am now able to pull it through two compressions without the piston going in the wrong direction and it starts and sounds great. Of course, I still would like the cord to pull like it always did but am happy that I found a work-around.

MintCreekFarms

First post-- Had same problem way hard pull. Removed plug pulls normally. Bar oil ran from plug hole. Sprayed carb cleaner,drained, replaced plug. pulled 5 times --running good. Thanks guys. Really helped.
JaP

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