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accuratelawn
05-04-2004, 09:26 AM
Little help.
25 Kohler on Lazer Z. 1800+ hours.
New plugs and battery. Fuel pumps works and all filters in good shape.
Problem... no spark when testing spark plugs. Motor turns over, but will not start.
Any ideas?
Thanks in advance.

mastercare
05-04-2004, 01:16 PM
Check the solenoid. The lazers actually have 2 of them. the obvious one is one the starter. The second one doesn't even look like a solenoid. It's on the battery cable between the battery and starter. It's black with two posts sticking right up. Mounted on the frame. They're about $15, I've replaced 2 of them now. Although, if the engine is turning, maybe that's not it. Good place to start though. Try using a jumper cable from your battery to your starter. If it fires, then the solenoid (which you're bypassing) is probably your problem.
Hope this helps.

AirCooled
05-04-2004, 04:19 PM
As goofy as it sounds, the problem may be as simple as the battery connected backwards. If thats not the case, first thing you need to do is determine if the problem is in the engine or the Lazer wiring. The Kohler's use a white wire for ignition "kill". Look for the harness plug coming out of the engine and disconnect the white wire. If you have spark, the problem is on the Lazer side of the harness. If still no spark, then the problem is on the engine side.
The 25hp uses that spark advance and needs power when the key is in the "ON" and "Cranking" positions. The easiest place to check power is at the carburetor fuel solenoid. There are two diodes in the engine harness and if one goes out you will only have power in one of the two key positions.

Hope this helps.

specialtylc
05-04-2004, 07:38 PM
Ignition coils are bad.

dishboy
05-04-2004, 07:54 PM
Originally posted by specialtylc
Ignition coils are bad.

How did you determine that?

I would check that all your conections for safety switches[like blades, nuetral for wheel drive etc.] are connected and making good contact as well as all wiring leading from ignition switch to ignition module, a 12 volt test lamp may be of some help in checking this.

specialtylc
05-04-2004, 08:11 PM
Originally posted by dishboy
How did you determine that?

I would check that all your conections for safety switches[like blades, nuetral for wheel drive etc.] are connected and making good contact as well as all wiring leading from ignition switch to ignition module, a 12 volt test lamp may be of some help in checking this.
Well my mowers wont crank over if the saftey switches are acctivated or not working. 99.9% probabilty its the coils.

Zachary52902
05-04-2004, 08:53 PM
I just had the same problem with my bobcat zt200. i replaced the ignition coils and it fired right up. I would say it is the ignition coils. That would be the first place i would start.

DLCS
05-04-2004, 09:25 PM
Originally posted by specialtylc
Well my mowers wont crank over if the saftey switches are acctivated or not working. 99.9% probabilty its the coils.


Right, most safety switches keep the motor from turning over. I would replace the spark plugs then check the coils.

AirCooled
05-05-2004, 10:05 AM
Why does everybody insist on replacing parts at random until the thing works? There is a systematic way of finding the problem but most people rather listen to what worked for one person and hope it works on his. I must laugh at coils because in most cases I think it would run on at least one coil being a twin cylinder.
I listed a systematic way to find the problem. Try it, its really not that difficult.

Goodguy001
05-05-2004, 12:13 PM
Aircooled is correct.
First check voltage to eng. should be at least 7.2v in the run and start poss. at the double red lead at eng connector. If thats good, pull the cover, check air gap. check secondary resistance to module (coil) 1 lead to laminations and other to sark plug term. resistance should be 7900-18400 ohms. either above or below then you know coils are bad. But both at same time a little odd
good luck

AirCooled
05-05-2004, 12:31 PM
I like to check voltage at the fuel solenoid to make sure the diodes in the engine harness are good. The red wire that feeds the solenoid is the same wire that feeds the "spark advance", but much easier to get to.
Accuratelawn also stated the battery is new. If its simply connected backwards, the starter will turn the engine over but the engine won't start. Maybe we should see if he's got it going before we beat this thread to death.

accuratelawn
05-16-2004, 08:11 PM
Thanks guys,
It was a very simple fix. The plug on the back side of the ignition had either worked loose or it was simply dirty. I pulled if off, cleaned it, and reinstalled.
Started right up!

Jimmyed
05-16-2004, 10:07 PM
Originally posted by AirCooled
Why does everybody insist on replacing parts at random until the thing works? There is a systematic way of finding the problem but most people rather listen to what worked for one person and hope it works on his. I must laugh at coils because in most cases I think it would run on at least one coil being a twin cylinder.
I listed a systematic way to find the problem. Try it, its really not that difficult.

From his explanation it says coils, id check kill wires, I don't think both coils went bad at once, though ive seen it.

AirCooled
05-17-2004, 02:02 PM
Originally posted by Jimmyed
From his explanation it says coils, id check kill wires, I don't think both coils went bad at once, though ive seen it.

Then I don't suggest you go to Vegas.:D