so your small engine won't start and won't run and you think it's because it doesn't have any
spark I already have a video on my channel I'll put a little link up here for you in
the information button as well as at the end of this video I've got some clickable thumbnails
there for you too that video is also waiting for you at the end you did everything up that video
and you tested the spark and there's absolutely definitely no spark coming out of the end of that
spark plug it's not necessarily your spark plug that's at fault it could be your high
tension lead it could be your ignition module your coil it could be some wiring problems in
there it could be your on/off switch but we want to rule out the spark plug right now let's go
hey guys welcome back to Steve's Small Engine Saloon again stevesmallenginesaloon.com right
there or visit my website when you get a chance yeah I don't think I've had a Coors Light with
you guys yet excellent beer now I know this video is going to take longer than one minute obviously
for me to explain this all to you but once you actually know all this information that I'm
going to show you right now by the time you take your spark plug out and test this it shouldn't
take you more than a minute to figure out whether your spark plug is the culprit or not you need a
multimeter guys if you don't have a multimeter man these things are so inexpensive I've got a
link on my description of this video so click on that link and you'll go back and you'll see some
some multimeters they're ridiculously inexpensive everybody should have one of these couple quick
things here for you when we're testing this spark plug first when we're testing this we
want to make sure that we're putting that spark plug laying it down on a non conductive surface
not a metal surface or anything like that put on a rag piece of cardboard something like that so
we're not getting a false reading also when you use your multimeter leads don't touch the metal
parts like that don't hold them on there the multimeter itself is going to read resistance
through your body believe it or not so make sure that you hold the leads on the insulated parts
like that when you're doing this now I got this awesome little visual aid here for you from
NGK so we can actually see the inside of a spark plug and I can I can describe to you a little
bit more about what I'm talking about I'm not getting sponsored or endorsed in any way shape
or form from NGK so let's just get that out of the way right now this is just a visual aid that
they provided for me you can see from this pic right here that there's two separate parts to
a spark plug a lot of guys call this the center electrode and the side electrode so that's what
I'm going to call it we call it whatever you want the center electrode goes down through the middle
right from where your boot hooks on right there and it goes right through the middle of your spark
plug right down to the point where that spark is coming out the side electrode is completely
separated from that and it's right here with the threads are and where your spark plug wrench your
socket fits on right there that is completely insulated from each other those two things are
insulated from each other by this white part of your spark plug that is a ceramic piece that is
all one piece it goes right through here like that and it's a solid piece now that's very important
I'll tell you why in a second now there's two types of spark plugs that you're gonna find
typically on your small engine equipment there's a non resistor spark plug and there's a resistor
spark plug we're gonna go through both of those right now we're gonna start with this one right
here this is a BM6A you'll see in the part number there is no R in that that means it is
not a resistor spark plug so what we want to do right here is turn our multimeter on and we want
to check for conductivity continuity through the center electrode how we do that is we're going to
touch right where the spark plug boot goes on right here and then we want to touch the other end
right in that insulate in that ceramic insulation right there the tip of that that's your center
electrode we touch that and you hear that that's continuity on my multimeter you touch those leads
together like that it reads no resistance it's just straight continuity through there that's
what we want to have on a non resistor spark plug straight continuity you can see there that there's
like no resistance there that's good the center electrode on that one is good now what about
a resistor spark plug then let's try a brand-new this is a brand-new BPR6ES it is almost in
every single-piece of your Honda equipment on your lawn and garden equipment lawn mowers all
that stuff this is brand-new now you're gonna see when I do the same thing on this one as well by
the way BPR6ES it's got the R in there means it's got a resistor in it here's how you're gonna
see that do the same thing now look at that now we're getting that ohms reading the ohms reading
is that little horseshoe shaped thing right there yes I understand that's the the Omega letter in
Greek it's also I just call it a horseshoe it's also the symbol for ohms you'll see that come up
on your multimeter if you don't have an automatic multimeter you have the dial on there make sure
for a resistor plug that you have that turn to the ohms that little horseshoe shaped thing
and check it again and we should have this one here is brand new plug and it's got just under
five thousand ohms of resistance right there and that's perfect that's what you want to have by the
way when you're doing this I've got to add this also when you're actually touching that central
electrode right there make sure that there's not a big piece of carbon or something stuck on there
where your one of your multimeter leads is just stuck on a piece of carbon make sure it's metal
to metal so you're getting a true reading if you have to clean the spark plug off with a wire brush
and get that carbon out of there do that first I know that there's a lot of videos out there
that actually guys will say on a resistor spark plug it needs to be between 4,000 and 6,000 ohms
of resistance if it's past 6,000 then your spark plugs garbage I got to disagree with that in the
small engine industry that might be true in the automotive industry but I'm not a car guy here's
a plug right here that is such a typical plug it's a BPMR7A this is on so many different
weed eaters and chainsaws out there BPMR7A the R is in there it's a resistor but I've tried I got
all kinds of I pulled about four or five plugs out tried am I tried a brand new one and the
resistance on those things is about nine or ten thousand see that one right there ten thousand
and I tried a brand new one and it was about nine thousand something like that so I have to say that
in in this industry if you have if you check a resistor spark plug and it sits around ten it's
probably okay if it's over ten I've never seen one over ten unless it's a blown spark plug if
it's over ten thousand ohms of resistance throw it in the garbage get yourself a new spark plug so we
tested the center electrode on those spark plugs on your non resistor plug if you're not getting
any continuity through that at all throw it out on the resistor spark plug if it's not getting
any continuity or if the ohms range the resistance is out of spec get rid of that spark plug too now
if we go back to this picture right here the next thing we want to check after we know that
that center electrode is good we want to check to make sure that there is no conductivity no
continuity between the center electrode and the side electrode how we do that as we put one side
of the multimeter on that tip right there and the other one on the side right here there should be
no conductivity no continuity all your multimeter should not move one little bit because that
ceramic insulator right there is supposed to be completely separating those and insulating those
from each other this is the garbage plug watch this I'm going to put that end of the multimeter
right there and push it on here and look at that we got some resistance that multimeter just moved
right there that should not happen that spark plug is also garbage the reason for that could
possibly be that the ceramic insulator that's going all the way through here operating those two
it could be that there's a little hairline crack but in that insulator somewhere in that ceramic
that's causing the voltage to leak through from the center over to the side in in this
area somewhere anywhere in there that should not happen that's of garbage sparkplug so if
you just tested all that out right there and you either ruled out that your spark plug actually is
faulty you threw it out and got a new spark plug excellent or maybe you confirm that the spark plug
is actually good and it still should be sparking but it's not now there's something else wrong with
your engine at least now you can move on now I know that there's a lot of you guys out there
who are gonna say right about now in the comments section saying well why not just take a new spark
plug and throw a new spark plug in there and see if it's got spark well yes you can do that
but I understand that there's a lot of guys out there who don't happen to just have a new spark
plug laying around where they can do that this takes less than a minute to do that what I just
showed you guys so I hope you like this I hope you give me that thumbs up button subscribe to
my channel if you already haven't and put some comments down share this with your friends as
always and I'm always working hard on the next video here she comes anytime soon Steve out guys