Engine 17 HP Kohler Starting Problems

[Greatwhitewing]

Well thank you very much for your detailed reply and kind offer to help along the way.

I have an acquaintance who does small engine repair. Actually my wife and his wife are good friends and I think I'll just muddle through this season jumping and let him fix it up over the off season.

I may try testing battery again, and bypassing ignition switch and solenoid again with and without spark plug to see what that reveals.

Much rather trash it get something zero-turn but that's not in the cards right now.

If you can suggest any other tests to help troubleshoot I am all ears.

Thanks again

A cam shaft is not a difficult job, but a big one with all of the cleaning & adjusting and of course it is an engine out job.
That is a fairly old mower so it is up to you if you feel it is worth it.
No problems with B & S cause their parts are cheap but Kohler parts are much more expensive.
My customers generally spring for a replacement engine & I give them a reasonable trade in on the dead one.
I keep telling myself that I will pull few down & make a good one or two out of them but it rarely happens .
Mostly I sell 3 to a novice racer for what I traded them for.
Parts books & service books are available directly from Kohler as a free download but I find it easier to go here https://www.mymowerparts.com/pdf/Kohler-Service-and-Repair-Manuals/
To do a cam shaft you will also need at least a sump gasket, rocker gasket & crankshaft oil seal.
In theory you can leave the head on.
I always take it off ( customer pays for the new gasket in any case ) to check the bore as I give 12 months on repairs.

If you want to go through with it then take lots of photos, particularly of the controls & springs on the controls.
We will be here to walk you through it.
Not particularly difficult but a first timers should allocate a weekend or two as just getting the drive pulleys off can be an all day affair.

 

[bertsmobile1]

In the dark remove the battery ground terminal.
If the rectifier has an open circuit diode the alternator will try to motor when the engine is not running which flattens the battery.
Other than that we ned the test voltages every one has been asking you for.

 

[Greatwhitewing]

I went back and read the thread, no one asked me for voltage readings. Just checked battery without charger on and get 12.90 V.

10.80 V at starter with key on. Funny thing is it turned over this time. Didn't do a thing since I last tried early today and it wouldn't crank with spark plug out. Been on charger for 3-4 days in float mode.

I will try your test when it gets darker. Am I looking for a spark? I think spell checker changed some of your words or I don't understand what you're saying about "alternator will try to motor..".

In the dark remove the battery ground terminal.
If the rectifier has an open circuit diode the alternator will try to motor when the engine is not running which flattens the battery.
Other than that we ned the test voltages every one has been asking you for.

 

[Greatwhitewing]

Assuming I was looking for a small spark taking off the negative battery terminal I saw NONE in a pretty dark garage.

I did put my Fluke multimeter in current reading mode measuring current from the battery to the disconnected ground lug. I measured 0.1 micro-amps which seems trivial since can read that with nothing connected (in the noise as I say) to the leads but I am no electrical engineer.

BTW I typically keep a battery tender junior connected between uses.

In the dark remove the battery ground terminal.
If the rectifier has an open circuit diode the alternator will try to motor when the engine is not running which flattens the battery.
Other than that we ned the test voltages every one has been asking you for.

 

[bertsmobile1]

Appologies I was confusing you with another non starting Kohler engine
Voltage across the battery terminals
1) everything off
2) ignition on
3) ignition on with engine running full speed
4) engine running full speed blades on

Do the same between the purple wire and a grounding point on the engine
Do the same between the purple wire and the battery neg

Then AC Volts between each of the white or yellow or black wires coming into the regulator should be over 28V AC
Followed by AC Volts between each wire & ground. Should be 1/2 the above
Then AC between the purple wire & ground. Should be 0

 

[Greatwhitewing]

1- Everything off 13.04 V after being on float charge all night
2- Ignition on 12.74 V

Wouldn't start under own power but did hear solenoid click. Jumped off non-running car battery and started well

3- Running full throttle 14.43 V
4- Blades engaged 14.42 V

I couldn't find a purple wire but I did measure rectifier. I labeled A, B C left to right in attached photo

A-c 45 VAC
A-B 0 (milli-volts) VAC
B-C 45 VAC

A-GND 200 mili-volts
B-GND 200 mili-volts
C-GND 45 VAC

If I can find the purple wire I can take those measurements too

Appologies I was confusing you with another non starting Kohler engine
Voltage across the battery terminals
1) everything off
2) ignition on
3) ignition on with engine running full speed
4) engine running full speed blades on

Do the same between the purple wire and a grounding point on the engine
Do the same between the purple wire and the battery neg

Then AC Volts between each of the white or yellow or black wires coming into the regulator should be over 28V AC
Followed by AC Volts between each wire & ground. Should be 1/2 the above
Then AC between the purple wire & ground. Should be 0

 

[bertsmobile1]

The 2 white wires are the AC that is being generated by the armature and between them you should see a bit better than double the DC charge volts ~ 28 V AC.
The middle wire is Rectified DC output to the battery and yours looks good if you are getting 14,3 V engine running with blades engaged.

So we can cross the battery off the criminal suspects list.

No sparks when disconnecting crosses a phantom load off the suspects list
A 1 volt drop is starting to look like a bad battery.

Try cranking the engine by connecting the starter directly to the battery .
You will get a big flash when you make the connection, so hook it to the starter first & then touch it to the battery.
If the engine cranks then you have a problem with the wiring in the mower.

Mowers left outside get corrosion happening in the heavy battery cables, inside the insulation because water wicks down between the wires & between the wires & the insulation.
These will test good with a volt meter but fail to carry the 100 amps needed to crank the engine.

 

[Greatwhitewing]

When it won't start under its' own power jumping directly from battery to starter doesn't work either. I have tried a number of times. My mower is 99% housed in a shed. I don't think it has been left out overnight when it rained, maybe but rare and not this year.

One thing that hasn't been replaced yet is heavy conductor wire(s). I have checked resistance previously, but not recently, and found it very low impedance.

What is the purple wire you spoke of before? What circuit or where does it run?

I will take the battery for another autozone test when I can, be a few days, pretty busy.

What I have trouble believing it's a battery is when it won't start a jump battery doesn't help unless it's attached to a running car

Thanks for your help

The 2 white wires are the AC that is being generated by the armature and between them you should see a bit better than double the DC charge volts ~ 28 V AC.
The middle wire is Rectified DC output to the battery and yours looks good if you are getting 14,3 V engine running with blades engaged.

So we can cross the battery off the criminal suspects list.

No sparks when disconnecting crosses a phantom load off the suspects list
A 1 volt drop is starting to look like a bad battery.

Try cranking the engine by connecting the starter directly to the battery .
You will get a big flash when you make the connection, so hook it to the starter first & then touch it to the battery.
If the engine cranks then you have a problem with the wiring in the mower.

Mowers left outside get corrosion happening in the heavy battery cables, inside the insulation because water wicks down between the wires & between the wires & the insulation.
These will test good with a volt meter but fail to carry the 100 amps needed to crank the engine.

 

[bertsmobile1]

Purple wire is the black wire in the middle of the rectifier.
Not seen a black one before but there are a lot of things I have not seen before which is why I am here.

Take the spark plug out & try to crank the engine.
If it cranks plug out but won't crank plug in the you have confirmed an internal engine problem.

Sorry I should have suggested this a lot earlier but it is one of those things that happens when you are looking at a screen & not a mower.

 

[Greatwhitewing]

I tried that a day or two ago and all I got was a solenoid click, no cranking. That time I jumpered from battery positive terminal directly to starter, no crank.

Later same day when I was checking something else in response to a suggestion here the mower cranked under it's own power. Very odd behavior IMHO. Most of the time it's won't crank under it's own power but sometimes (rare) it surprises me.

Purple wire is the black wire in the middle of the rectifier.
Not seen a black one before but there are a lot of things I have not seen before which is why I am here.

Take the spark plug out & try to crank the engine.
If it cranks plug out but won't crank plug in the you have confirmed an internal engine problem.

Sorry I should have suggested this a lot earlier but it is one of those things that happens when you are looking at a screen & not a mower.