Kohler engine no spark till coasting.

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
93
Messages
11,589
That's basically it. With experience come knowledge of how to do things. Sometimes it is better to just let a professional do the work as he has done the investing his time and money in having whatever is needed to do the job. Beside it is a lot less frustrating but of course some think we are just gouging them.

Sorta like the time a customer decided he was a better tech than my lowly shop was. He spent over $400 and still had to bring the mower into the shop for me to spend 15 minutes and find a fifty cents terminal bad. But of course he wanted me to make whole again by buying his used parts.

I just pass the 47 yrs of electrical troubleshooting experience and yet there are times it takes some head starching due to some unusual wiring.
 

ILENGINE

Lawn Royalty
Joined
May 6, 2010
Threads
44
Messages
10,775
Sorta like the time a customer decided he was a better tech than my lowly shop was. He spent over $400 and still had to bring the mower into the shop for me to spend 15 minutes and find a fifty cents terminal bad. But of course he wanted me to make whole again by buying his used parts.

I just pass the 47 yrs of electrical troubleshooting experience and yet there are times it takes some head starching due to some unusual wiring.
Had a customer bring me a Briggs 5 hp in a box totally disassembled down to the bare block, because it wouldn't start and he couldn't determine why. I totally has to reassemble the engine to determine what the issue was. In the end found that it had a faulty spark plug.

And you are right about the wiring on some of these mowers. Some of the wiring on mowers make you say WHAT.
 

mcostello

Active Member
Joined
Jun 10, 2012
Threads
10
Messages
71
There are no letters visible on the back of the switch after I cleaned it up gently. I do not have a lot of small engine electrical experience. I have a small machine shop and weld, turn, bore and otherwise do metal repair. I have a lot to learn about small engines.I clean and rebuild carbs.
The terminal marked B goes to the amp gauge, gauge goes to left side of regulator. Terminal on top goes to top of regulator to ground. This is as far as I got. Will continue tomorrow. Will run down more wires tomorrow. I have battery voltage to the coil with the switch in the run position, no voltage to coil in start position, but the engine coasts when letting off on the key and starts when coasting.
 

mcostello

Active Member
Joined
Jun 10, 2012
Threads
10
Messages
71
Yes My electrical troubleshooting is weaker than I like, but I am learning. I had to go into town today and had to drive past O'reilly's twice. I decided to drop in and see what They had. I found the switch referred to above and it works. I thank Every one that has helped Me with this problem.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
59
Messages
15,349
I’ll bet if you look carefully you will will find letters stamped on the metal terminals.
 

VegetiveSteam

Well-Known Member
Joined
Jun 1, 2022
Threads
0
Messages
447
Yes My electrical troubleshooting is weaker than I like, but I am learning. I had to go into town today and had to drive past O'reilly's twice. I decided to drop in and see what They had. I found the switch referred to above and it works. I thank Every one that has helped Me with this problem.
Glad you got it.
 

mcostello

Active Member
Joined
Jun 10, 2012
Threads
10
Messages
71
No letters on terminals, letters on new switch are almost under the terminals, old switch is too old to see,new one just barely. Looks exactly the same. will check patent numbers shortly.
 

ILENGINE

Lawn Royalty
Joined
May 6, 2010
Threads
44
Messages
10,775
Yes My electrical troubleshooting is weaker than I like, but I am learning. I had to go into town today and had to drive past O'reilly's twice. I decided to drop in and see what They had. I found the switch referred to above and it works. I thank Every one that has helped Me with this problem.
Most peoples electrical troubleshooting skills are not what they would like. It takes times to get competent at it and I didn't say good. the thing with auto electric or small engine electric is sometimes you have to go slow to go fast. It has to be done step by step and follow the system, because you may miss something by jumping around.

I would say i am not the best. Part of my skills come from experience and mistakes along the way. If you are into watching Youtube look up Eric O with South Main Auto. This guy is probably the one of the best electrical auto troubleshooters on the web. This guy get the stuff that is towed in from the 3rd dealer and had several thousand dollars worth of parts thrown at them and they ask him to diagnose or repair them. And will show his system of diagnosing problems with vehicles. I would say he has probably doubled my working knowledge of how to troubleshoot issues. He for the most part doesn't work on small engines but what he shows when he goes through his techniques on cars and trucks will also apply to troubleshooting small engines.

I’ll bet if you look carefully you will will find letters stamped on the metal terminals.
Some have them on the terminals some are printed on the backing plate of the switch. there are a few out there that are unmarked. there is was period that one of the companies that I worked with sent out a bulletin saying the terminals on their keyswitches would be unmarked.
 

mcostello

Active Member
Joined
Jun 10, 2012
Threads
10
Messages
71
No patent numbers on new switch. Old key fits new switch. New key too big to fit old switch, filing will fit that, just for reference.
I took the old switch apart,because I am like that. and the switch was not burned out or anything. It was functioning as intended, just the wrong switch for the application. Thanks all, Mark.
 

TobyU

Well-Known Member
Joined
Jun 1, 2014
Threads
0
Messages
563
No patent numbers on new switch. Old key fits new switch. New key too big to fit old switch, filing will fit that, just for reference.
I took the old switch apart,because I am like that. and the switch was not burned out or anything. It was functioning as intended, just the wrong switch for the application. Thanks all, Mark.
I kind of doubt that unless the mower has always agreed this way....I forget the previous discussion on that. Lol
Of course a switch should send power to that coil even in on position AND in cranking position.
Did you get a new switch that looks identical to the old?
If so.... It's 99.9% likely the same switch application and it will have power in on and cranking AND your old one should too!
I've seen several of these and similar do the same thing.
They don't make contact on cranking position sometimes just due to some corrosion or spring pressure being weak or the plate inside flexing.
Also seen them blow ignition modules due to slightly bridging 12v to kill switch term a you turn switch (usually to off) as it only takes a millisecond.
 
Top