Stihl 084 AV Ignition Coil

[jsoluna]

Hey guys,

I'm a mechanic by trade and recently had a customer bring me an 084 AV Stihl Chainsaw in need of repairs. There's no spark at the plug, and I've come to the conclusion that the ignition coil is fried. Not entirely uncommon, I hear. Problem is that I cannot find a replacement coil anywhere, used or new. I know they're NLA from Stihl.

Coil Part Number:

1124 400 1308

Any leads?

Thanks!!!!

Justin

 

[Giles]

I read an old post describing how to SOMETIMES Revive a defective coil.
Of course this will not work everytime because if the coil is "fried" ---it won't.
His suggestion was to remove the spark plug and also to lubricate the cylinder wall, and make sure the clearance between the flywheel and coil is correct---app. 012. Proceed to spin the flywheel with an electric drill, at about 2,000 rpm, being sure rotation is in the right direction. C/C in most cases. Flywheel may have to be spun for a length of time but I had results within a few seconds from a DEAD coil.
I am fortinate enough that I have a Lathe and it is a simple matter to set the components up and run the procedure.
I had TWO dead coils and this worked on both and the saw has continued to work.
These modern day coils are complicated because many change the engine timing and also limit the maximum rpm.
Much better then a point type ignition because at 13,000 rpm there would be "floating" and other problems.
Good Luck--might work for you and it will cost nothing

 

[jsoluna]

Thanks

I also tried seeing if condensation internally in the coil was the problem, let it get nice and warm atop my wood stove, no luck. I've fixed a lot of Lawn Boy 2 cycle coils this way, at least temporarily.

 

[Wood Doctor]

(1) Check all wires for continuity first and then use an ohmmeter to check the resistances. See the service manual.

(2) Remove the coil and clean the heck out of it and the area around it. Also, polish up the flywheel. Then replace the coil.

If there still is no spark, replace the coil, but I have revived two of them using step 2 and made sure that there was no ground out. Figure that saw may have 500 or more hours on it. Old beasts sometimes need special treatment.

 

[William Balaska]

I might have one of thes give me the number right off the coil. I forget if they had an external trigger (not under flywheel) Anyway I got a box of parts send me a number.

 

[Wood Doctor]

I might have one of these. Give me the number right off the coil. I forget if they had an external trigger (not under flywheel) Anyway I got a box of parts send me a number.

Both of the 084s I fixed did not have an external trigger as shown in the service manual. Could be that Stihl discontinued them after awhile. Finding 084 parts around here is like looking for a needle in a haystack. These saws are monsters from the lagoon but many loggers still love using them. When they run right, they can outbuck about everything out there.

Keep in touch, Bill. I may need your help.

 

[jsoluna]

Previously checked continuity between ground and kill wires, checked continuity between ends of wires themselves, and tried running coil without the kill wire attached. That's the basics of what I checked when I started leaning towards the coil itself being suspect. I've been advised by another member to double check the spark plug leak, particularly at the plug end, so I'll do that today. Hopefully I've just missed something in my diagnostics. Thanks guys

Justin

 

[blsnelling]

Not all 084s had the same ignition. Some had a trigger, others did not.

 

[jsoluna]

Thanks for all the advice guys....I cleaned connections, cleaned coil and flywheel as well as mounting points, even replaced the lead wire from coil to plug and still no spark. Looks like I'll need a coil.


William - I tried sendin ya a PM, but it says your inbox is full

 

[Dennis Cahoon]

Any of the 064/066 coils will work. What you have to do is match the bolt pattern of 2 of the 3 mounting holes, then sand or grind the radius to match the 084 coil. It works, I've done it many times.

 

[Wood Doctor]

What About An 088 Coil?

Any of the 064/066 coils will work. What you have to do is match the bolt pattern of 2 of the 3 mounting holes, then sand or grind the radius to match the 084 coil. It works, I've done it many times.

That's good to know. Where there's will, there's a way!

I have to wonder if an 088 coil will work also with the 084 and perhaps without modificaton. Anybody know? These seem to still be around.

 

[RiverRat2]

Any of the 064/066 coils will work. What you have to do is match the bolt pattern of 2 of the 3 mounting holes, then sand or grind the radius to match the 084 coil. It works, I've done it many times.

Good on ya Cahoon!!! Hahahahahahahahahaha!!!

 

[galde]

I read an old post describing how to SOMETIMES Revive a defective coil.
Of course this will not work everytime because if the coil is "fried" ---it won't.
His suggestion was to remove the spark plug and also to lubricate the cylinder wall, and make sure the clearance between the flywheel and coil is correct---app. 012. Proceed to spin the flywheel with an electric drill, at about 2,000 rpm, being sure rotation is in the right direction. C/C in most cases. Flywheel may have to be spun for a length of time but I had results within a few seconds from a DEAD coil.
I am fortinate enough that I have a Lathe and it is a simple matter to set the components up and run the procedure.
I had TWO dead coils and this worked on both and the saw has continued to work.
These modern day coils are complicated because many change the engine timing and also limit the maximum rpm.
Much better then a point type ignition because at 13,000 rpm there would be "floating" and other problems.
Good Luck--might work for you and it will cost nothing

This was my post. It generally works for those modules that go dormant from long periods of non-use. I don't understand the inner workings of the solid state components in a module, but if it works I don't need to understand why.

 

[jsoluna]

I tried that trick too, forgot to mention. No luck! Anyone have a used coil they'd want to get rid of?

 

[broman78]

my 084 has coil 1122-1314 installed which is a 066 coil. I'm not sure if the previous owner had to adjust the timing, but I think he did because there is a 2"x 3" rectangle cut out of the fan housing. Hope this helps.

 

[Yellowbeard]

I'm now in this same boat. Getting no spark on my 084. Has anything changed on this issue since? Anyone know where to get coils, for example? If not, I'll try the 066 thing but I would love to know if I need to change the timing.

Thanks!

 

[big t double]

I have done it recently with the 1122 400 1314 coil. I was lucky and had the flywheel with two key slots. The old 084 coil was the rev limited cdic coil. I moved the flywheel to the correct slot and it worked great....however I could only get one mounting hole to line up. The owner of the 084 still is undecided if that's how he wants to run it so the saw is still sitting in my basement.

 

[Yellowbeard]

I have done it recently with the 1122 400 1314 coil. I was lucky and had the flywheel with two key slots. The old 084 coil was the rev limited cdic coil. I moved the flywheel to the correct slot and it worked great....however I could only get one mounting hole to line up. The owner of the 084 still is undecided if that's how he wants to run it so the saw is still sitting in my basement.

My local dealer had that part (1122 400 1314) in stock. It certainly looked, when we lined it up with the old coil, like only one bolt hole would line up (I just walked in from dropping it off). However, my mechanic said he could use a strap to reach the other bolt. Can you tell me any more about this flywheel with two key slots? Is that something I should have my mechanic look at?

Thanks!

W.C.

 

[big t double]

i don't know if all 084's came set up with the dual keyway slots but i believe the later ones did...ive only worked on one...but the later ones changed from the cdic(limited) ignition to the ey-v(unlimited) ignition coil...similar to the 064/066...if you use the 1122-1314 coil, it would be considered unlimited so i changed the flywheel to the slot marked "B"...the cdic coils ran on the "P" slot. the change from the cdic to ey-v happened somewhere around 1995. check your serial number. if its after 131237198 it already has the ey-v coil and you can rock and roll...if its before you'll need to check your flywheel, hopefully you have two keyways. I'm not sure when they changed from the trigger style to the cdic though...if you had the trigger style you might not have a two way slot....someone that knows more than me would have to chime in on that one....heres a little more info...if your 084 coil is part number 1124 400 1306 it is the cdic...if its 1124 400 1308 is the unlimited. if you do end up making a strap id be interested in seeing what you come up with!!!

 

[Wood Doctor]

This thread fascinates me because I have an 084 sitting on the floor. It starts and runs, but it will not slow down to idle. I rebuilt the engine and it has spectacular compression. But, for some reason, the idle will not drop down to below 4000 RPM regardless of idle setting or low-speed carb setting. Other than that, the saw is a beast.

What's the easiest fix?