Spark

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Fish

Tree Freak
Joined
Apr 22, 2001
Messages
13,967
Location
Loretto/Manton Ky.
Folks test and see a spark, so they say that the spark is good...........

They say it shocked their pinky, so the spark is good.

They go by spark color, but that is quite subjective...........

Lot's of spark questions today, I thought I would just throw this out there....

Favio is a Daddy, he is not shootin blanks, and he gave me this cute little hand rolled cigarillo...... So I am quite reflective.........

Running problems are tough to isolate, that is why I make the real big bucks.........................................................................................................................................................................................................................................................................................
 
Guarddog1

Guarddog1

ArboristSite Guru
Joined
Oct 17, 2008
Messages
503
Location
Upstate New York
I have seen spark that appeared good but when it was apposed by the pressure of compression there was not enough energy to make it jump the gap. Try diagnosing that puppy. (But again that is why fish makes the big money.
:bowdown: Just joking fish do not take offense.)
 
mweba

mweba

Addicted to ArboristSite
Joined
Mar 22, 2009
Messages
4,251
Location
iowa
Amazes me how many people try changing the spark plug last or never for that matter.
Had no spark on the 028 day before the GTG, threw a kawasaki electronic ignition trigger on it and away I went.
 
Guarddog1

Guarddog1

ArboristSite Guru
Joined
Oct 17, 2008
Messages
503
Location
Upstate New York
The method I use to test for good spark is with a gap of around 8mm but thats for a motorcycle. Maybe my test gap wouldn't be so large for a saw.

One time I inadvertently checked the spark on my YZ I was taking the plug out and my brother kicked it over while I had my hand on the wire and HOLY CRAP they give out A LOT of volts and FFAASSTT. That was a heck of a learning experience I believe it was more volts that and vehicle.
 
motomedik

motomedik

ArboristSite Operative
Joined
Dec 5, 2007
Messages
141
Location
In a cloud of wood or metal chips
One time I inadvertently checked the spark on my YZ I was taking the plug out and my brother kicked it over while I had my hand on the wire and HOLY CRAP they give out A LOT of volts and FFAASSTT. That was a heck of a learning experience I believe it was more volts that and vehicle.

That's one way to check the spark intensity!
 
J.W Younger

J.W Younger

ass kissing impaired
Joined
Jul 11, 2008
Messages
28,981
Location
a world of isolation
Intresting thread. I just checked my owners manual for the 5100 and the recommended spark plugs had an R in the number. Thats a resistor plug I'm thinkin. Why in hell does a chainsaw need a resistor in the plug?
must be somea that gubberment mandated ####.
 
heimannm
Joined
Dec 28, 2005
Messages
12,956
Location
Dike, Iowa
I was checking out my SIL's little Stihl before the GTG Saturday morning. We had it running about two years ago but it had been setting in his garage since then. Tried to start it and nothing. Pulled the spark plug and no spark. Of course I decided it must be something serious deep inside, but my brother suggested trying a different spark plug; fat, blue, snapping spark, and the saw was ready to go.

This has happened to me once or twice before. I can't quite understand how this happens to a saw that is just setting around but spark plugs are cheap, and struggling with a saw for an hour or two only to find out the spark plug was the problem is annoying.

Of course you can struggle for a long time on an old gear drive saw only to discover you were spinning it backwards (with the recoil started off of course).

Mark
 
Rookie1

Rookie1

Addicted to ArboristSite
Joined
Apr 19, 2008
Messages
6,199
Location
Suburb of Cleveland,Ohio
I dont know the reason but Ive been told resistor plugs make 4 cycle mowertype engines start easier. I would assume it carries over to 2 strokes.As for testing spark I use an inline tester. One that lights up,After a while you can tell the difference between good an weak spark. :)
Oh Fish, Dont all wives test husbands for their ability to handle pressure?
 
J.W Younger

J.W Younger

ass kissing impaired
Joined
Jul 11, 2008
Messages
28,981
Location
a world of isolation
I dont know the reason but Ive been told resistor plugs make 4 cycle mowertype engines start easier. I would assume it carries over to 2 strokes.As for testing spark I use an inline tester. One that lights up,After a while you can tell the difference between good an weak spark. :)
Oh Fish, Dont all wives test husbands for their ability to handle pressure?
wonder how that works. a resistor requires more electrical pressure(voltage)
for a given amperage
1volt to push one amp tru a resistance of 1 olm........last time I checked.

olms law not mine
 
eyolf

eyolf

Addicted to ArboristSite
Joined
May 5, 2001
Messages
1,916
Location
Mini soda
These cheesy little magnetos on small engines just don't have a whole lot of power. Resistance in the plug holds the spark back for part of a nano, until it fires with everything its got.

Think 7th grade and a spitwad in a soda straw. Put a loose-fitting spitball in the straw and blow: the spitwad flops out slowly and doesn't go far. Then make a bigger one that fits the straw; now you gotta blow harder, but once it goes you can make it all the across the hall and land on the window next to Mrs. Woodes' desk.

Undetected, if you're careful...and Alex S. gets the blame!

Not that I'd actually know, of course....
 
dragrcr

dragrcr

Addicted to ArboristSite
Joined
Jul 9, 2009
Messages
1,074
Location
ca
when i was in school (auto tech) in arizona, we were in a performence class, and in the middle of a dyno run, i went to advance the timming ever so slightly, the motor has a MSD digital 10 system with 2 coils... i sat on the floor for probably 10 minutes before i got my marbles back into place enough to get up.... damn worn out spark plug wire boots!
 
Elmore

Elmore

Addicted to ArboristSite
Joined
Feb 27, 2004
Messages
2,291
Location
North Alabama
Resister Plugs

Intresting thread. I just checked my owners manual for the 5100 and the recommended spark plugs had an R in the number. Thats a resistor plug I'm thinkin. Why in hell does a chainsaw need a resistor in the plug?
must be somea that gubberment mandated ####.

They call for resistor plugs on newer equipment because a non-resistor plug may interfere with electronic ignitions...also they mess with your AM radio reception!
 
Last edited:
J.W Younger

J.W Younger

ass kissing impaired
Joined
Jul 11, 2008
Messages
28,981
Location
a world of isolation
They call for resister plugs on newer equipment because a non-resister plug may interfere with electronic ignitions...also they mess with your AM radio reception!
yeah, this is for sure one of the reasons, LOL.
but there may be something to rookies theory also, think about a water hose with a nozzle on the end. I think rookies thinkin would difinently help with a wide plug gap but most saws have a narrow gap like.025 or closer.This is the kinda stuff that makes us think
now my head hurts.
 
john taliaferro

john taliaferro

Addicted to ArboristSite
Joined
May 12, 2009
Messages
1,153
Location
springfield missouri
msd

stop your hart,you get dizzy,then thump thump she starts yep you just slid in by the skin on your teeth. the car was not running the key was on and i was twisting dist. i bet some of these new saws could hurt you bad.
 
056kid

056kid

Addicted to ArboristSite
AS Supporting Member
Joined
Nov 10, 2004
Messages
6,634
Location
On the road
Folks test and see a spark, so they say that the spark is good...........

They say it shocked their pinky, so the spark is good.

They go by spark color, but that is quite subjective...........

Lot's of spark questions today, I thought I would just throw this out there....

Favio is a Daddy, he is not shootin blanks, and he gave me this cute little hand rolled cigarillo...... So I am quite reflective.........

Running problems are tough to isolate, that is why I make the real big bucks.........................................................................................................................................................................................................................................................................................





Wtf.


are you a fruit loop?
 
056kid

056kid

Addicted to ArboristSite
AS Supporting Member
Joined
Nov 10, 2004
Messages
6,634
Location
On the road
yeah, this is for sure one of the reasons, LOL.
but there may be something to rookies theory also, think about a water hose with a nozzle on the end. I think rookies thinkin would difinently help with a wide plug gap but most saws have a narrow gap like.025 or closer.This is the kinda stuff that makes us think
now my head hurts.

Wide gaps are for 4 strokes.


my 250r will ##### & moan all day long with anything over .025...
 

Latest posts

Top