spark plug question

[bstewert]

Today my 192T would flat not start. It ran 3 weeks ago, but today couldn't even get it to sputter. I tried new gas, still nothing. The plug looked pretty fouled, but it's late Sunday eve and nowhere to buy a new one. So I cleaned it up and reset the gap to .20. Still nothing. Do plugs reach a point of no return? The contact points still look good.

 

[sotc]

Check for spark first or make sure the wires on the magneto have not come loose or broke

 

[lumberjack]

Generally speaking, the only way a spark plug fails is if the insulator breaks allowing a short of if the conductor/electrode breaks allowing an open.

 

[Al Smith]

That saw is set pretty rich .The plug should be a tannish color instead of sooty black .A whitish color would indicate too lean .FWIW I've never seen a plug actually go "bad " on a saw or any other small engine .

 

[MasterBlaster]

What was that Mike Maas said, so very long ago???

 

[woodworkingboy]

A wire brush is a good way to clean up a plug, then a blow with the compressor. I give it a rub from time to time as a part of regular maintenance.

 

[lumberjack]

Something about $20 bucks for every worn out plug!

 

[woodworkingboy]

I think this is Mike:
"Seriously, the odds of the new plug being bad are about the same as the odds of the old plug being bad. So you're stuck in an infinite cycle of changing out the new plug with another new plug, knowing this one could be bad too. One day they'll try to get into the room where you were working on the saw. It'll be hard to get in because of the huge pile of spark plugs and you'll be covered with so many they'll have smothered you to death.
After they dig your body out they'll find a half opened spark plug box. The plug can then be mounted permenently in your headstone with a caption that reads: "This one could be bad too, who knows?"

 

[MasterBlaster]

I sure hope Mike's OK and didn't go off the deep end over the death of his daughter. So sad...

 

[Al Smith]

Ha Ha .Good old Mike .I remember when about 20 jokesters changed their avatars on a certain site with Mikes picture on them

 

[Al Smith]

You can get kind of screwed up on plugs if you don't pay attention to what you're doing .With few exceptions unless it's an antique all plugs use a 14 MM 1.25 thread .The heat range and head size can vary though plus weather they are resister or non resister types .Best to do some research before you change one .

With Stihl nicely the large nuts on the bar and the plug size is the same .Else like the other brands you need about half a dozen different sizes of scrench in your tool box and you can never find the damned thing when you need it

 

[woodworkingboy]

If I could start a band, I'd call the group 'fat blue spark'.

 

[treesandsurf]

I hope Mike is doing all right, I think about him every now and then and wonder how he's doing...

jp

 

[bstewert]

Check for spark first or make sure the wires on the magneto have not come loose or broke

Thanks, Willie. I forgot to do that, assuming it would be OK since the saw doesn't have very many hours on it. Checked it this morning. It had a good spark and all the wires looked perfect. I cleaned up the plug again until it was shining. Nothing.

Put in a new plug and it started right up.

 

[HolmenTree]

Do plugs reach a point of no return? The contact points still look good.

When I first read about your contact points , I thought "a 192T doesn't have contact point ignition" but then I see you were referring to the plugs contacts.
I have had issues with NGK plugs becoming duds without a warning or when my saws start to idle poorly, just pop in a new one. Even some of the Bosch plugs made in Brazil or India have these same issues. I still have a stock pile of German made Boschs and have never had a problem with them. I have used them since the 1970s .
Damn good plug, just getting harder to find these days.

 

[bstewert]

The old plug was a NGK, and the new one I put in today is a Bosch.

 

[HolmenTree]

The old plug was a NGK, and the new one I put in today is a Bosch.

 

[Al Smith]

Very seldom will a plug actually fail .It could be the fact that the plug is gas fouled causing it to malfunction which can happen although rarely .

It gets enough carbon built up on it that rather than jump the gap to produce spark it takes a ground path through the carbon and no sparky .

 

[woodworkingboy]

It goes without saying that a plug needs the proper gap or close to it. Has that been mentioned? If you dropped it on the slab and didn't know about the gap, it could mess you up.

 

[Bermy]

Yes he said he reset the gap...

 

[bstewert]

Yes, I checked the gap first thing, even when it was dirty. Today I spoke to a guy at a repair shop who said sometimes when a plug gets fuel-fouled it's pretty hard to revive them. Fortunately plugs don't cost very much. This is the 2nd one I've had where just cleaning it didn't help, one on another tool that doesn't get used very often.

Who else here has a 192T? I usually just take it in for carb adj, but would like to know how to do it myself.

 

[woodworkingboy]

Do you know what the manufacturer's specs are for the adjustment screws, i.e. how many turns out? If so, why don't you try that setting first. Post again if that doesn't seem right to you in the way the saw runs. it's not difficult, just takes your ear learning what it wants to hear.

 

[Cobleskill]

Reading the plug will tell you if you are in the ball park. Tan/brown and your good. The new strato saws run black one side and white on the other, so not to much help there. It isn't easy to hear the sweet spot on a strato with a rev limiter either. It's starting to get like working on new vehicles, cat converters, next thing we will have fuel injection. Computer adjusted carb is here already I have been told.

 

[Greenhorn]

Yes, I checked the gap first thing, even when it was dirty. Today I spoke to a guy at a repair shop who said sometimes when a plug gets fuel-fouled it's pretty hard to revive them. Fortunately plugs don't cost very much. This is the 2nd one I've had where just cleaning it didn't help, one on another tool that doesn't get used very often.

Who else here has a 192T? I usually just take it in for carb adj, but would like to know how to do it myself.

I had a little mini sand blaster deal that was designed for cleaning plugs with compressed air etc. With that I could revive them from that state, but not with b-12 alone, like usual.

 

[Al Smith]

Champion make a little blaster about a zillion years ago that not only blasted the plug but also tested it . They are probabley considered to be a collectable antique of automobile stuff .