I'am an old past prime diesel mechanic and not up with electronics.What is the mode of failure of modules and the cause,has anyone repaired one.??Frank C.
There must be someone here that know how they operate and what causes there demise.I would think they have something like a zener diode that will dump when the voltage reaches a certin point.When I replace one I'll unpot that rascal and see whats in there,you know its a cheap little diode that fails. Frank C.
You have a couple transisters and basically it works by detecting the max rise on the sine wave .
Here's one example .http://www.foxvalleykart.com/timing2.html
You could cut one apart I suppose but the danged thing is epoxy encapsulated and you'd be real lucky to get it apart in such a way you could recognise anything.
Thanks Al, I understand now and can stay away from pot. Frank C.
Pot :o What's that got to do with anything ?
Nonsense aside for all intents the sealed solid state ignition moduals are non repairable .I would imagine it probabley has to do with the moduals inability to dissipate the heat generated from the saw engine .Most likely the solid state switching circuits which use transisters of a sorts just can't cut the heat .
Over the years I've had a few go bad but not really that many .
I forgot to mention I've seen solid state ignition do some crazy things especially the self advancing type .
One on either a Stihl 042 or 048 that would not advance and the poor old saw just chugged away at about half throttle .Another on a Briggs 18 HP that would full advance and kill the engine under a certain speed .It about burned the starter up trying to start it with a hot engine .50 bucks later and one new modual it was back in business .Other wise it was wait two hours drinking beer under the big umbrella on the patio until it cooled off .The price for the beer soon exceeded the price for the modual .
Thanks Al,your probibly correct on the heat.The husky 55 with the failed module had sawdust packed around the module.My saws, I blow them out with compressed air after sharpening. Frank C.
I've never cooked one but I've had one give me fits.Old Mac PM 610 that I still own .Shut it down hot and then you wait a half hour to get it started .
It never dawned on me because I thought I had kept it blown out .Come to find out the bottom of the cylinder was packed tight as a bulls butt at fly time with chips.Couldn't see it until I needed to take the shrouding off .It's a wonder I didn't cook the thing but it still runs and well after 30 plus years .
After thought here .Owners of Stihl 200t's and 020T's need to heed the fact these saw will pack chips under the cylinders also .I mean tight too .So much so you might need to deshroud them to clean them out .Pricey little thing .Too nice of a saw to let cook itself .
I remember back in the 80's my brothers dirt bike had a cracked Ig. Mod. It was bolted UNDER the seat right by bottom of gas tank & seat junction. when he got it someone had taken straight "T" pin and pushed it into the thing to jumper SOMETHING out or around and as long as you didnt touch that PIN with it running it did pretty good. Ya I found out DONT touch that sucker when it was running! and my brother found out dont hit a BIG mud puddle while riding it as it was just under the set that when the seat & pants got wet the family jewels made a good connection up thru the handle bars 8) :D :o smiley_eek_dropjaw
Mark
:D I've got a 2100 Husqvarna that the kill switch portion doesn't work so I spliced a kill wire from the plug to a ground switch .The danged thing will throw fire about an inch .I lit another guy up at a GTG fooling around with it .I mean that SEM coil is one hot rascal .I'd about bet that thing could light of kerosine .
Quote from: Al_Smith on January 31, 2013, 08:57:54 PM
After thought here .Owners of Stihl 200t's and 020T's need to heed the fact these saw will pack chips under the cylinders also .I mean tight too .So much so you might need to deshroud them to clean them out .Pricey little thing .Too nice of a saw to let cook itself .
Got one on the bench right now, pretty sure thats what has happened.
Ed
It's not just the 200's but more so any horizontal cylinder saw .
In this day and age I'm not sure other than trim saws if anybody makes a horizontal cylinder saw .The vert cylinders don't seem to have the problem of keeping the chips cleared although they can still pack them up around the ignition modual .
It's just a thing you don't think about until after the fact .