Testing spark from your coil/s

The information presented here applies to most all motorcycles in general.
Post Reply
m2h
Scooter Enthusiast
Posts: 205
Joined: Mon May 23, 2016 12:24 am
My Bike: 03 VS1400
Location: Waipu Northland NZ

Testing spark from your coil/s

Post by m2h »

Here's an easy to make tester to load up the coil to check for a strong spark. Would like to give credit for this but can't remember where i found it.

As you can see from the pic it's a 3" nail on one end with a few grooves filed or ground in the end to fit the plug cap. The other, just some thread bar with a point on. the gap is 7mm. Earth to engine some where. Turn engine with both plugs out and check spark. If its not consistent or not there you have a weak coil. Or something deeper in the mix It's down and dirty but quick.
Image
M2H
" Old Guys Rule!" :rock:

User avatar
WintrSol
Joined a 450cc Club
Posts: 857
Joined: Fri Feb 26, 2016 2:02 pm
My Bike: CB450 GL1500CT
Location: Near St. Louis, MO

Re: Testing spark from your coil/s

Post by WintrSol »

Great idea, but I wouldn't use wood. The moisture in wood can cause it to carbon-track, bypassing the gap. Get a block of nylon or similar plastic at a hardware store, or even use a plastic box that has walls rigid enough to hold the points.
Florissant, MO
CB450K3, GL1500CTValkyrie

m2h
Scooter Enthusiast
Posts: 205
Joined: Mon May 23, 2016 12:24 am
My Bike: 03 VS1400
Location: Waipu Northland NZ

Re: Testing spark from your coil/s

Post by m2h »

WintrSol wrote:Great idea, but I wouldn't use wood. The moisture in wood can cause it to carbon-track, bypassing the gap. Get a block of nylon or similar plastic at a hardware store, or even use a plastic box that has walls rigid enough to hold the points.
Good plan ^ only used wood cos that was all i had at the time :cheers:
M2H
" Old Guys Rule!" :rock:

User avatar
WintrSol
Joined a 450cc Club
Posts: 857
Joined: Fri Feb 26, 2016 2:02 pm
My Bike: CB450 GL1500CT
Location: Near St. Louis, MO

Re: Testing spark from your coil/s

Post by WintrSol »

In college, we used a neon sign transformer, about 20kV, and welding rod to make a Jacob's ladder. We drilled holes in a board to hold the rods, and it eventually failed. You could see the lightening-shaped tracks forming around the rods, then it started to smell.
Florissant, MO
CB450K3, GL1500CTValkyrie

User avatar
scootermcq
Joined a 250cc Club
Posts: 590
Joined: Mon Jun 01, 2015 6:15 am
My Bike: VS1400 + VL1500
Location: Ontario, Canada

Re: Testing spark from your coil/s

Post by scootermcq »

This sure fire method is free:



:lmao:
Scott

Image

User avatar
Herb
Joined a 1200cc Club
Posts: 19122
Joined: Sun Oct 26, 2014 9:28 pm
My Bike: 1999 1400 intruder

Re: Testing spark from your coil/s

Post by Herb »

Back when I was about 13, a friend and mine were building a go cart, we had an old Homelite chainsaw engine and couldn't get it to start. We didn't know if there was any spark. Didn't have a spark plug wrench, I told my 5 year old brother to hold on to the plug wire to keep it out of the way. He said no, it would shock him, so I handed him a pair of pliers and told him to hold it with them. Gave a hearty pull on the starter rope, the pliers went about 20 feet in the air, he screamed and ran for the house yelling for mom. When she came out to see what had happened, and I told her what we had done, she had trouble keeping from laughing, but no problem with grounding me to he house for a week...
I can't seem to win the lottery. I think I have used up all of my good luck riding motorcycles.

navigator
Joined a 1100cc Club
Posts: 5429
Joined: Thu Dec 29, 2016 12:33 pm
My Bike: VS800

Re: Testing spark from your coil/s

Post by navigator »

Better grounded to the house than the magneto. :lmao:

User avatar
Herb
Joined a 1200cc Club
Posts: 19122
Joined: Sun Oct 26, 2014 9:28 pm
My Bike: 1999 1400 intruder

Re: Testing spark from your coil/s

Post by Herb »

navigator wrote:Better grounded to the house than the magneto. :lmao:
By the end of the week she was so sick of me...
I can't seem to win the lottery. I think I have used up all of my good luck riding motorcycles.

00Vs1400GLP
Learning My Moped
Posts: 130
Joined: Fri Dec 30, 2016 10:16 am
My Bike: 2000 Intruder 1400

Re: Testing spark from your coil/s

Post by 00Vs1400GLP »

http://shop.advanceautoparts.com/wcssto ... i_larg.jpg

These are fairly cheap, have an adjustable gap, and work well. For those who dont have the tools or desire to build your own. That said, I love the DIY approach to things. It's great when you see a problem and find a way to solve it using what you have.

User avatar
Herb
Joined a 1200cc Club
Posts: 19122
Joined: Sun Oct 26, 2014 9:28 pm
My Bike: 1999 1400 intruder

Re: Testing spark from your coil/s

Post by Herb »

I like these because they allow you to see the spark with the engine running. Also if the plug is dead, they won't spark. If the plug is shorting out, like they do with a cracked insulator, it will still show a spark.

Used to have one that I bought through JC Whitney, years ago (I won't say how many), but loaned it to someone and never got it back.

https://www.walmart.com/ip/Lisle-Inline ... 3=&veh=sem
I can't seem to win the lottery. I think I have used up all of my good luck riding motorcycles.

Post Reply