CDI Spark Tester

[FabricGATOR]

What spark tester is recommended. I'm considering an upgrade from my pseudo sparkplug with an alligator ground clamp.

I remember sequoiha, rodbolt and 99yam40 endorsements, but I can't seem to find it in the forum today.

[99yam40]

depends on what you are trying to do and what motor you are checking.

Adjustable gap testers are very good and multipoint are also good if checking multi cylinder spark all at once.

Inline shows spark while running

inductive Timing light will also indicate if plugs are getting spark current flowing through the plug wire

some can be made easily with block of wood some nails or screws and some wire

Open spark can ignite gas fumes so be careful

[FabricGATOR]

I'm running a pair of SX/LX150TXRY's and doing my own maintenance. So I wanted to have a good piece of equipment to make my life easier.

I'm experiencing missing and stalling on the SX but when I get her warmed up and running, she dries out and seems good. Then when I throttle back and they are awash, she breaks up again and usually stalls at an inconvenient time.

I was swapping the 5 and 6 coils with the 3 and 4 and noted that I had a cut in the insulation on an ignition wire and corrosion. Wish I could change the wire like on a motorcycle.

I could also have an injector not producing full atomization...

I'd also like a real pressure gauge for the VST stem. I keep ruining my tire gauge.

[99yam40]

Rodbolt says his KV tester is great for finding low spark voltage.
Locating intermittent spark is tough

most problems end us a fuel related, but you never know until you check.

Spark testers are just to see if it is getting spark to plugs, if looking for quality of spark besides jumping a gap you need to be measuring voltages into and out of coils and maybe ohms of coils, wires, and caps

good Pressure gauges made for fuel rails and such usually have a pressure release on them to keep fuel from spraying everywhere when disconnected

[seahorse5]

This might help with building a spark checker

Build Your Own Outboard Spark Tester | Boating Magazine

[FabricGATOR]

Snap-On MT2700 DIS/kV Ignition Probe

I wonder if Rodbolt has this KV tester.

Thank you seahorse5 That is similar to what I have done for years, except not so many at once.

I have the manufactured alligator clamp on the generic spark plug tester. It gives a visual indication and an audible snap.

I am looking for something to evaluate the quality of the spark and to quantify a value. I know, I may be going overboard with all this. A sharp blue flame has always been good for me.

How about those inline neon tube testers. Will they indicate if a plug were fouled or not firing? I suppose if the plug were shorted, the volt will find ground through the light and illuminate.

[FabricGATOR]

I'd be able to use my old inductive timing light.

[99yam40]

my old snap on inductive timing light worked on my C40TLRX, but I had to hook it up with the arrow pointing away from the plug for it to work

A KV tester = kilo(1000) volt meter that will tell you how many volts it puts to the plug to jump its gap or go to ground if it is shorting out

[jb123]

A spark issue wont" clear out" like fuel will
Yes time for a good pressure gauge and fuel system maintence

[rodbolt17]

no I don't own 1 MT2700, I own two.

super handy dandy tool once you realize how much BS you have been fed about super duper flame thrower mag fire crap coils.

electricity is very very lazy.

the ign coil is simply an inductive transformer similar to the one in your cell phone AC charger.

the spark tester I use is the stevens S-48 twin setup that can test up to 8 leads at once.

once a spark of 7/16ths of an inch is observed we can now move on to the Kv.

Kv= thousands of volts.
typically on the single electrode Yamaha you will see about 6-8KV when running normally.
remember the 7/16ths spark test was good, means all the parts are capeable.

now if one cyl was running say 2Kv and the rest at about 8Kv this tells me I have an issure on THAT cylinder.
rich fuel mix = low Kv, foulded plug = low Kv, loss of compression = low Kv.

some reasons for high KV, excessive electrode gap, bad cap resistor or wire to cap connection,high compression or lean a/f mixture.

see
I have been on you boat 10 minutes with a compression tester,a spark tester(these two tests are done at the same time) and my Kv tester I have either confirmed which cylinder is failing or none are failing continue on.

[FabricGATOR]

MT2700 DIS/kV

Thank you guys for your input.

Very interesting information from Rodbolt. I had not thought that the environment within the cylinder would effect the voltage (rich, low compression) the fouled plug, I could imagine, that may increase the resistance and therefore change the value.

Additionally, Rodbolt good troubleshooting methodology tutorial.

I just bought a MT2700 DIS/kV. I look forward to incorporating it into my tool chest and skill set.



As previously stated, upon inspection of my #5 ignition coil, I found a cut in the HV wire and it appears corroded inside. I wish I didn't have to buy a complete coil assembly to get a good plug wire on that cylinder.

[boscoe99]

"If its got teats or tires, you bound to have trouble with it...."


Or, if it flies, floats or f___ks, it is better to rent than to own.

[FabricGATOR]

Fly's, Floats' or Fornicates

You sound like an aviator Boscoe

I've got all three.....

[FabricGATOR]

I have my KV tester

Hello again.

I just received my StrapOn KV tester. I practiced on the wife's Honda Civic so I loosely experienced what it was and how to use it. I have the instructions.

Yesterday I went at the problematic engine. Recap, she sputters, idles low, stalls more that runs smooth. If I manually raise the idle speed with the control, she'll begin to clear the (foul) first one cylinder then another. and then she'll kinda idle regularly until she's shut down for a time and cools off. Frustrating during mooring operations to have her drop offline and just become a secondary rudder.

SX150TXRY

Clip this thing on the spark wire. Starting at the low KV setting either the conventional or inverted light will illuminate. Slowly dial the knob up until the light goes out, then back down until it just illuminates or flashes irregularly. This is your cylinder firing voltage. Compare to other cylinders.

KV tester: After warmed up spark wires tested running in the 7 to 8 KV range.
Cylinders 3 and 5 (stbd side 2nd from top and bottom) were unusual to me as with this tester there is both an "inverted" and "conventional" light that depends on what type of ignition system we are running. 3 and 5 both lights illuminate, conventional drops off around 5Kv and Inverted drops off around 10Kv. The other cylinders are conventional only and drop off around 7Kv. I figured that the inconsistency was the two cylinders being "shut down" at lower idle rpm's. Now I see that it is cylinder 2 and 5 that are designed to drop off.

I've learned here that the majority of idle problems revert to fuel delivery issues.

I removed the air box and noted a slight corrosion at the bottom of the throttle bodies where the butterfly is in close proximity the aluminum airway. Opened the throttle and was able to grind (only kidding) just using my finger and a little oil residue found in the airway, clean the majority of the corrosion away. One airway has only the ever so slight feel of minor pitting.

Just reporting what I found of my amateur irregularity readings on the KV tester.

Time ran outlast night, so I didn't have opportunity to compare with the port engine.