(mechanical music) - Hey, guys, welcome back to
my small engine repair channel. Today, I wanna show you
guys a quick and simple way to diagnose your engine if you have no spark. Now, what I'm gonna show
you in the video today, anybody can do this at home, as you're going to see. It's so easy to do, and it's going to save
you a lot of aggravation when you're trying to
diagnose a small engine, whether it's a four cycle engine like this a chainsaw, weed whacker,
lawnmower, whatever you have, it will help you to diagnose quickly whether you have a coil, which is the ignition
module on your engine that produces spark, or if
you have a wiring problem causing you to have no spark. So, the reason I'm making the video is I get a lot of emails
and comments on YouTube, people are asking me, I've just put in a brand
new coil or ignition module on my engine, and I
still don't have spark. So, by the way, for all
of you guys watching today that are new to small engines, your coil, or sometimes
called ignition module, is this part here that
bolted outside the flywheel. And, basically, this part
here, the coil produces the spark to your spark plug, and on your chainsaw, it's located usually right here on the side of the recoil assembly. There it is right there. All you need to do, the procedure I'm going to
show you in the video today is a small pair of pliers, like this. And the procedure I'm going
to show you today, again, is, if you have no spark at the spark plug of your outdoor power equipment. And, obviously, before you check anything, make sure you have a good spark plug. So, first of all, to check for spark on your small engine equipment, you need to take the plug out, get it far away from the spark plug hole, and ground it on the engine. And what you have to do is make sure the switch is on, to
check properly for spark. Now, on this chainsaw
here, I do have spark. (chainsaw whirring) But let's say I had no
spark on this chainsaw, even if I had replaced the coil, which there isn't right now, because I've turned the switch off. (chainsaw whirring) But the point of the video
is, if you have no spark and your switch is on, this
is what I'm going to show you how to bypass the electrical system, which includes the
switch that turns it off. So, I left the switch
here in the off position to simulate an electrical problem. And, as I just showed
you, there is no spark. So, what you would do, in this case, to figure out very quickly whether you have an
ignition module problem or an electrical problem is
to disconnect this wire here from the primary tab
of the ignition module. And, again, it's the
tab that is not grounded to the machine itself, to the metal. So, this wire here is grounded, so you stay away from that. It's the primary tab
that you want to remove. So, again, as I've mentioned previously, when you remove the wire
from the primary tab, you are actually detaching the coil, or separating it completely
from the wiring system. So, if there's a problem
in the wiring system and you've disconnected
that, you will get spark if your coil is good. So, just have a look here. (chainsaw whirring) Now, you can see I've got spark. (chainsaw whirring) And, like I said, I have
turned the switch off to simulate that, but since
I disconnected the wire, it's bypassing on the switch. (chainsaw whirring) So, the whole gist of this video here is to help you to quickly diagnose whether you have a bad coil
or a bad wiring system. So, it's very simple, but, remember, if you
do disconnect this wire, you've got spark now, and you start up the machine,
the switch will not work because it's totally disconnected
from the ignition module. So, just be careful, because that can become
a safety issue as well. So, just have a plan to quickly
pull the spark plug boot off or turn the choke on
to stop it immediately. And then you would know, okay, I need to go in and fix either the switch or some of the wires that may be grounding on the metal parts of the engine. Now, on the other hand, if you disconnect that wire
and you still don't have spark, then you need to replace the
ignition module or regap it. Now, when I say regap the coil, what I mean is you loosen the
two bolts that hold the coil, you bring the flywheel
around where the magnet is, and you basically put a spacer or a 10000ths of an inch feeler gauge between the coil and the
flywheel where the magnets are, and then re-tighten up the bolts. I like to use a business card, because it's pretty well the correct size that you would need to gap a coil, and it's much easier to work
with than a feeler gauge. So, again, gap your coils at
around 10000ths of an inch. And, again, on this Honda engine here, you would disconnect the wire from the primary tab right here and check for spark once
you have removed that. So, it's very simple, guys. Just remember that, when
you have the wire off, basically the coil here
is working on its own. There's no outside
interference causing issues. So, to give you an example, let's say the mice had gotten in
this engine over the winter and the wires were frayed and the wire was actually
touching on the engine here while the wire's still plugged on the primary tab of the coil, it would be acting as a shutoff switch. Because this wire goes to the switch, and when you turn the switch off, it actually grounds
this tab to the engine, thus creating a no spark
at your spark plug. So, once you understand
that concept, guys, and you're working on small engines, you can diagnose a no spark
issue on an engine quite fast, and it would be the same
thing on a lawn tractor with a V-twin engine, except you'd have a little bit more stuff to take off to actually get at the coils, but it's not a big deal. And the same with the lawnmower here. You'd have to take some covers off, find out where the coil
is, it's right here, and find out where the wire goes to it, which is usually sometimes
hidden underneath. And, like I said, guys,
if the coil's disconnected and you still don't have spark, 99 percent of the time you
need to replace that coil if you've already tried to gap it. It's very rare that I end up
having to replace a flywheel, although I will recommend that,
when you have a spark issue and you've corrected it,
to go back to the flywheel and clean it off with a wire brush or a 400 to 600 emery paper, and make sure the magnets
are nice and clean, because they do tend to
rust, as you can see here. So, before ending off the video, I will just reiterate this again, because I made a short video in the past, and I realized I needed to come back and make a longer video. So, just to reiterate things, if you disconnect the primary wire from the primary tab here on the coil and you still don't have spark, more than likely you
need to regap the coil, or you need to replace it. And, on the other hand,
if you disconnect the wire from the primary tab, and, all
of a sudden, you have spark, then you have a wiring
issue on your equipment. So, check the switch
and check all the wires, and including this one here, where it goes in the electrical
system of your engine, and just go from there. Hopefully my explanation here is clear. If you have any questions on this subject, please comment below. I'll try to answer your questions. And also the viewers are also
great at answering questions that I don't always
have the time to get to. So, if you've learned
something today in this video, please like it and share
it with your friends. Also, make sure you're
subscribed to my channel, guys, because I put out videos
on a weekly basis. Thanks again for watching
and have a great day. (mechanical music)
