Stihl 028 AV Super - Help needed Plz

[Zolo]

Hi Guys, sorry about the long story,
i bought Stihl 028 AV Super last week from an old man. he was not sure about the history of the chainsaw but he said it was running few years ago. it was a very cheap deal. as far as i heard Stihl 028 AV Super is very reliable saw. so i cleaned the saw and put some two stroke in it and it fired after 5-6 pull. it was running very rough, i mean when it started chain was running dead fast so i thought there is an issue with carb so i tried to set the carb high and low screws, it was rev fine. but then i realize that the stop switch is not working. i believe there is an issue with coil or might be just with stop switch does not work.

I was unable to stop the saw, it took me couple of minutes to thing that how i am going to stop this machine. I pull the choke and chainsaw was running even faster which was very strange as in the past i was able to stop the saws by opening the choke if the stop switch does not work. also i realize by moving the saw in different directions and positions carburetor settings were getting wrong, is this mean that there is an air leak somewhere? or something to do with Crank seals or Crankshaft bearing? so finally i stopped the saw by changing the L screw to 0.

i am going to look into the saw again on the weekend, but any help would be highly appreciated. I love this forum as in the past i always got very good information and help from this forum so big thanks to people providing the help and advice.

 

[HarleyT]

Take off the air filter cover, and take some pics, your throttle control may have just popped up out of place.

Also, before trying to start it anymore, take off the bar and chain, a lot safer that way.

 

[Zolo]

thanks for your reply, i believe throttle control would be fine as soon as i stopped the choke, it was running fine again. so my question is why it was not shutting down when i was opening the choke while chainsaw was running. It should stop am i right?
also i will take some pictures tonight as well as will remove the bar and chain for safety.

 

[Ozhoo]

It's pulling in air from somewhere. When the choke is open it's getting enough air across the venturi to pull fuel into the engine. When you choke it down it's still getting air from somewhere else but now is way lean. Don't run it again till you go over it for leaks. Intake boot, crank seals for starters.

 

[Zolo]

thanks for your great information and help, how can i check the leaks without running the saw, is there any easy way to do it. I am kind of DIY person.

 

[LoveStihlQuality]

May just be killl wire off. When you tried to choke it off, did you squeeze throttle to get the switch all the way down to full choke? You possibly just got it to fast idle position. Have you ran Stihl saws before? The operation of the 4 position switch are all the same.. ps the choke is actually a spring flap inside the air filter.

Sent from my SM-N900P using Tapatalk

 

[Zolo]

Thanks LoveStihlQuality, much appreciated......
i believe you are right, I might not pulled the choke all the way down, I don't remember now but will check it tomorrow, also i will try to kill the wire off. I have run the stihl saw previously but i have little knowledge about chainsaws

 

[LoveStihlQuality]

If you're able to get some pictures of switch area with air filter removed it would help. I've always liked the 028s.

Sent from my SM-N900P using Tapatalk

 

[LoveStihlQuality]

If you're able to get some pictures of switch area with air filter removed it would help. I've always liked the 028s.

Sent from my SM-N900P using Tapatalk

Sent from my SM-N900P using Tapatalk

 

[HarleyT]

the kill wire/switch is part of the throttle control gizmo, which also works the choke/throttle, which is why I suggested a pic of that area, as a good pic usually reveals a lot.

 

[Zolo]

Thanks guys i will take a picture tomorrow morning. Thanks for your help and much appriciated. People on this forum are very helpful. I am loving it. Thanks zolo

 

[Zolo]

So i tried running the saw again took me bit of time to set the carb but it fired and was running ok. But still the kill switch does not stop the chainsaw and on the full choke chainsaw was not running at high speed i was unable to see any difference on the full choke or or normal start position. Not sure what is going on. I have also cleaned the yellow wire well as metal bit shown in the picture but still no joy. I have to change the low screw to 0 to stop the saw. I think whether the wire is faulty or the kill switch plastic assembly is not working as expected but i donot what i should be. I have uploaded some pics please let me know if anybody know the issue. Thanks

 

[Zolo]

Also what black wire does and if that wire does not work then what issues should i face? Thanks zolo

 

[HarleyT]

I would try first taking some emory cloth and buff the bullet end of the wire, and where it touches the metal spring, might just be a tad dirty there. If not, take off the pull starter and look, follow the wires, one goes to a grounding screw on the block, the other goes to the terminal on the coil.

 

[LoveStihlQuality]

Check the coil to be sure that kill wire didn't come off the tab and that no overheat or damage in that area.

Sent from my SM-N900P using Tapatalk

 

[LoveStihlQuality]

When troubleshooting a no spark, I'll pull kill wire off to narrow down coil or wiring problem. I did fubar one coil by breaking off the tab. Some have a locking tab that needs to be depressed to slide off.

Sent from my SM-N900P using Tapatalk

 

[SteveSr]

When troubleshooting a no spark, I'll pull kill wire off to narrow down coil or wiring problem. I did fubar one coil by breaking off the tab. Some have a locking tab that needs to be depressed to slide off.

ALL of the Stihl's that I have worked on have the locking tab. You have to bend it or at least depress it while pulling the terminal off. DON'T force it!

 

[atpchas]

While you're trouble-shooting your setup. leave off the air filter. Simulate the choke for cold starts by dribbling some mix into the carb throat. With AF off, your thumb can easily block the venturi to kill the saw until you get your electrical problem sorted out.

 

[Zolo]

Hi guys thanks for everybody help i beleive i have found the issue. There are two issues at the moment one is air filter back cover is missing. I have compare the filter with the original one at online and it is missing back flip cover. Which means the saw never triggers the choke. It is not woring due to air filter issue also when i touched the end of black wire with my screw driver the chainsaw stopped straight away. It looks like end part of black wire needs soldering so it can make decent contact with metal. I will get it fixed next weekend and i will order the brand new air filter. I will update you guys once evrything starts working. Thanks guys your help is highly appriciated. This forum is great help.

 

[155a]

Hi guys thanks for everybody help i beleive i have found the issue. There are two issues at the moment one is air filter back cover is missing. I have compare the filter with the original one at online and it is missing back flip cover. Which means the saw never triggers the choke. It is not woring due to air filter issue also when i touched the end of black wire with my screw driver the chainsaw stopped straight away. It looks like end part of black wire needs soldering so it can make decent contact with metal. I will get it fixed next weekend and i will order the brand new air filter. I will update you guys once evrything starts working. Thanks guys your help is highly appriciated. This forum is great help.

Zolo. I've encountered a similar situation to this. Your pics were a real help. Just bought a second hand 028avs. My circuit breaker wire is there but disconnected (I'm sure I can fix that). But my ground wire (green/yellow) is missing altogether. Obviously one end of the ground wire screws onto the spring as shown in your pics. Where does the other end fix to? Can you picture me when you're next under the hood? Cheers. Steve.