Engine Won't Start

Hello, first post... I have an older SCAG Turf Tiger with a Kawasaki FD661D - 22.0 motor. I blew a head gasket last fall so it set all winter. When I replaced the gasket I changed the oil and put in new gas. When we turned it over the first time is putted several times then nothing. Since then we have replaced the spark box and the kill switch. We have cleaned the flywheel contacts and changed the ignition switch and deck on/off switch. The engine turns over but I have no spark to the plugs at all. For some reason I have power to the coils at ALL times no matter what position the ignition switch is in, on or off. We have checked every connection on the unit for corrosion and connectivity, all are good. There has to be just one thing I am missing but need help. If anyone has any suggestions I would appreciate it, especially why the coils are hot all the time, that just does not seem right. Thank you in advance...

If you have constant power to the coils then the ignition module has failed or you fitted the wrong unit, there are several of them and they are not all the same.
At $ 300 a hit you really need to triple check the electronics before substituting parts.
It is always best to find the actual problem before you go swapping parts because if what caused a componant to fail remains the same all you will be doing is contributing to the parts suppliers retirement fund.
Kawasaki have all of their service manulas on line as a free download so no excuse for not testing the wiring properly

bertsmobile1 said:

If you have constant power to the coils then the ignition module has failed or you fitted the wrong unit, there are several of them and they are not all the same.
At $ 300 a hit you really need to triple check the electronics before substituting parts.
It is always best to find the actual problem before you go swapping parts because if what caused a componant to fail remains the same all you will be doing is contributing to the parts suppliers retirement fund.
Kawasaki have all of their service manulas on line as a free download so no excuse for not testing the wiring properly

Click to expand...

Thank you for the info. I purchased the spark module based on info in the service manual and used my SCAG serial / Kawasaki engine identification numbers, so it should be correct. The original reason I had replaced it was when we examined the part it had come apart and all the internal parts / wires were exposed. I will check the ignition module for correct wiring. Any other suggestions will be appreciated. Thanks again...

That module picks up a signal from the magnets in the flywheel then uses it to turn the coils on & off.
Basically it is nothing more than a set of points with an advance -retard built in.
Very robust & reliable, till they are not.
Check the wires where they go into plugs for a loose wire not making contact as wires can break inside at the terminal.

bertsmobile1 said:

That module picks up a signal from the magnets in the flywheel then uses it to turn the coils on & off.
Basically it is nothing more than a set of points with an advance -retard built in.
Very robust & reliable, till they are not.
Check the wires where they go into plugs for a loose wire not making contact as wires can break inside at the terminal.

Click to expand...

Checked the wires and the connectors and all seem tight and connected. The unit is new and all wires are color coded the same as the old one. My confusion is the coils are hot all of the time even if the other three wires (of the 5) on the module are unhooked, and even the ignition switch is unplugged. The ONLY time there is no power to the coils is if the power or ground wire on the module are unhooked. I even put the old module back on to see if the new unit was defective and it is the same, continuous power to the coils except when the power or ground wire was off. Do the magnets on the flywheel interrupt the flow of spark or tell the coil to make spark? If the magnets were bad would this allow power to the coils all the time? Also if the coils are hot all of the time it will / would run down the battery and that was never the case before this problem. Thank you again for your help and suggestions...

Check the relays

On the wiring diagram page 7-5 you see the Y/W wire that delivers power from the E terminal on the ignition switch directly to the coils.
So the coils always have +12 delivered to them, from the Y/W wire whenever the key is on.
That supply should be switched by the ignition switch so measure it to ground, if it is still there ignition off then the ignition switch is faultly or is wired wrong.

The black / Yellow wire goes to the igniter module and it grounded to make the coils fire.
I originally forgot that this is a Kettering ignition, not a magneto ignition.
If the coils are working properly they should spark whenever the ignition is turned on and the B/Y wire is grounded or ungrounded.
They should also be electrically isolated so neither terminal should show continuity to ground with the spark plug wire removed.
Some times there is an insulator on the mounting bolts to ensure that the coil is isolated.

As the igniter grounds the coils, to collapse the field & induce the spark in the secondary winding, if the coil is getting a ground from any other source then it becomes a poor output resistance heater.

The two small coils near the flywheel are the electronic version of a set of points.
When the magnet passes them it generates a small voltage which travels to the Igniter Module .
The Igniter Module waits a set amount of time ( milli seconds ) then closes the B/Y wire to the coil to ground which should cause the coil to fire.
The time delay varies according to the voltage the Pulsor coil generate
Being that the faster a magnet passes a coil the higher the voltage the coil generates.
So the delay in closing the B/Y wire varies to advance the spark .
In reality , the advance is simply less retard as you can slow electricity down but you can not speed it up.

As previously mentioned, a really great system, while it works and it is what makes these engines so good .
The same applies to the Kohler magnum series.
However when they don't work they are a PIA so Kohler abandoned their variable timing when they brought out the new models.

SO turn the ignition on and make & brake the Yellow / White wire at the individual coils with the B/Y terminal jumped to ground
They should fire at every make & break but the make will be smaller than the break so you might only see it with a meter.
Repeat without the jumper wire and there should be no spark

Likewise , with the ignition turned on you should get a spark every time to jump the other terminal to ground.

If the Igniter Module is working you should get make & breaks between the Black / Yellow wire & ground when the crank is being rotated.

Now because the entire triggering system is a GROUND circuit, it has to be isolated from GROUND everywhere and a short to GROUND is a very hard thing to find.
IT could be nothing more than a dirty plug on one of the connectors, a missing or squashed isolating washer.