Inductive Timing Light Hook-Up

[rrichtarek]

I have an 8hp Wisconsin Robin EY27W that my son and I have rebuilt for a go-kart. The good news is that it started on the first pull. The bad news is that at high RPM it misses and will backfire when you back-off the the throttle. I've spent conderable time trying to remediate this issue through carb adjustments (it's a NOS carb). I took the spark-plug gap to .28 and that seemed to help a little. Now I'm onto timing - new points/condenser were installed during rebuild and set to .14 per service manual but I want to be more precise. My question is where do you connect the hot lead on an inductive timing light? Do you need to? (haven't tried yet)

 

[Mad Mackie]

The inductive pickup on most timing lights is too big to get around the short sparkplug lead/wire. The sparkplug lead can be temporarily extended by using a neon sparkplug tester which usually will give you enough lead to be able to clamp on the inductive pickup of the timing light. A caution, if the sparkplug tester has any metal as part of the tester, keep the inductive pickup away from the metal and closer to the sparkplug. I'm not sure what the problem is but I had several timing lights fail in the inductive pickup as result of making contact with the metal portion of a sparkplug tester.
I periodically use a timing light to troubleshoot an engines ignition system as on almost every gasoline engine there is no provision to change spark timing.
Check out this link as there is Kohler info here.
Ignition Solutions for Small Engines and Garden Pulling Tractors
Mad Mackie in CT:laughing::smile::biggrin:

 

[BlazNT]

There is not a place to point the light to on a single cylinder motor. Timing light will not work. But to answer your question it connects to number 1 spark plug wire.

 

[rrichtarek]

There is not a place to point the light to on a single cylinder motor. Timing light will not work. But to answer your question it connects to number 1 spark plug wire.

The WR has a mark on the flywheel and "D" and "B" alignment marks on the crankcase. Tech manual has a two-wire timing light (non-inductive) with hot going to main coil (plug) wire and one ground with kill switch disconnected. I can get my hands on an inductive timing light, but those are designed to be powered by 12v battery and since the we're deriving spark from the magneto/flywheel I'm curious if the hot lead needs to be connected.View attachment WR-EY27_ServiceManual.pdf

 

[rrichtarek]

The inductive pickup on most timing lights is too big to get around the short sparkplug lead/wire. The sparkplug lead can be temporarily extended by using a neon sparkplug tester which usually will give you enough lead to be able to clamp on the inductive pickup of the timing light. A caution, if the sparkplug tester has any metal as part of the tester, keep the inductive pickup away from the metal and closer to the sparkplug. I'm not sure what the problem is but I had several timing lights fail in the inductive pickup as result of making contact with the metal portion of a sparkplug tester.
I periodically use a timing light to troubleshoot an engines ignition system as on almost every gasoline engine there is no provision to change spark timing.
Check out this link as there is Kohler info here.
Ignition Solutions for Small Engines and Garden Pulling Tractors
Mad Mackie in CT:laughing::smile::biggrin:

Thanks for the tip keeping the pick-up away from the metal, fortunately the plug/coil wire is quite long and provides ample room. More importanly, thanks for the link - for magneto they state: " Use a test light with battery power..." which suggests another tool purchase unless I find someone with a battery powered light that I can borrow!

 

[Mad Mackie]

The WR has a mark on the flywheel and "D" and "B" alignment marks on the crankcase. Tech manual has a two-wire timing light (non-inductive) with hot going to main coil (plug) wire and one ground with kill switch disconnected. I can get my hands on an inductive timing light, but those are designed to be powered by 12v battery and since the we're deriving spark from the magneto/flywheel I'm curious if the hot lead needs to be connected.View attachment 22822

I power my inductive timing light from a 12 Volt battery. If an engine has breaker points it will have timing marks. I usually remove the blower housing, find the timing marks and stick on a piece of reflective tape. An engine can be run for a short time with the blower housing removed. Some engines have a removable screen which exposes the flywheel. Manual start engines will need a rope or strap wrapped around the cup to start them with the blower housing and recoil starter removed. The link that I sent you has an upgrade for Kohlers, but can be installed on some other makes, that is partly solid state and uses the breaker points as a switch to trigger the spark in the solid state device. The points can be easily set with a timing light and no longer need a condenser, the high amps that pass thru the points in a stock setup no longer happens, the solid state device carries the coil amperage draw, the points just trigger it. The points will stay in adjustment and last much longer. If the blower housing is attached to a cylinder head bolt(s) then the bolt needs to be retorqued before running the engine and after the blower housing is reinstalled.
Mad Mackie in CT:laughing::biggrin::smile:

 

[BlazNT]

Wow I was tough incorrectly.

 

[rrichtarek]

I power my inductive timing light from a 12 Volt battery. If an engine has breaker points it will have timing marks. I usually remove the blower housing, find the timing marks and stick on a piece of reflective tape. An engine can be run for a short time with the blower housing removed. Some engines have a removable screen which exposes the flywheel. Manual start engines will need a rope or strap wrapped around the cup to start them with the blower housing and recoil starter removed. The link that I sent you has an upgrade for Kohlers, but can be installed on some other makes, that is partly solid state and uses the breaker points as a switch to trigger the spark in the solid state device. The points can be easily set with a timing light and no longer need a condenser, the high amps that pass thru the points in a stock setup no longer happens, the solid state device carries the coil amperage draw, the points just trigger it. The points will stay in adjustment and last much longer. If the blower housing is attached to a cylinder head bolt(s) then the bolt needs to be retorqued before running the engine and after the blower housing is reinstalled.
Mad Mackie in CT:laughing::biggrin::smile:

I tried with an inductive that I borrowed this afternoon, connected it to my car battery, and hooked-up without the engine running (spin hard!) - while I could generate spark I couldn't get the timing light to flash - so as you stated, I would need to wrap a rope and try from there. However, I've gone with a simpler solution that requires little effort - Magneto timing tool: Action Air Parts 62584 Standard Single Magneto Timing Light - LED51N at SkyGeek.com

I read about the solid state device and I'm very intriqued - I also learned from the same link that high-end variations can result from worn crank/cam shaft bearings which may be something else for me to examine if I don't get the results needed with the timing. Thanks for your help!

 

[Mad Mackie]

The points can be set with a continuity light which is a flashlight with plugin power leads. I had forgot that I had one that I used years back for setting the points on low HP Johnson/Evinrude outboard motors. I use the inductive timing light for troubleshooting higher RPM problems as you have mentioned. My inductive timing light is 1978 vintage and modified to operate up to 10,000 RPM, still working but on its 3rd inductive pickup!!

 

[motoman]

It's been ten years but I remember using my automotive inductive timing light on my Intek V. I'm pretty sure I clamped the spark plug lead and grounded the other end, but I do remember how weak the light was and weak red, not white. Anyone can establish an accurate TDC, but takes a little time. I have one prick punched on the Intek. It is at the leading edge of the coil when bolted in place. If you are running 5000 rpm or more seems you need an advance curve of some sort or the engine will break up due to imcompatible timing.