The STX I just got had a bad lower brg in the PTO clutch. The cage had come apart and the balls were roamin free. They could get all on one side and act like a one way roller clutch. I could tell something was up because when I would try to turn the cooling fan screen I could hear the PTO clutch bang into the anti rotation peg. When I got home and pulled the pto clutch ( which fell right off ) then the crank turned freely.

You could pull the sparkplug and see if the motor spins as it should.

 

I have the top tin off so I can see the starter gear.. can also turn the engine by one finger till I get compression stroke.. then a lil hard..

 

I just thought of sumthin.. could it b the IGN switch doin all of this.. will give that a check tomorrow..

 

When you use the remote starter sw make sure you turn on the ign sw or else you gets no spark. I have an assortment of jumper wires with various terminals and clips so I can run motors with the chassis wiring harness disconnected. To protect the charging system it's best to either hook the VR output to the batt or to disconnect the stator leads from the VR.

 

here's the big question of the day.. since the big battery cable is hooked to the solenoid.. & I apply 12 volt to the lil terminal.. Y doesn't the starter spin when the gear engages the flywheel.. neither of the 2 starters spin.. I can sit on the seat with both pedals down & the IGN switch in the on position.. the starters should spin when 12 volt is goin (via my test switch) to the lil terminal..

 

BTW, I didn't detect a question in the above text... Did you omit it?

Edit: Oh... "Y doesn't the..." Gotcha.

 

What I did on that STX was remove the starter and hit it with 12v .

This unit had been sitting for quite a while under a small lean to and was pretty rusty. Initially the stater wouldn't spin so I used the dipstick to apply some engine oil to the top bushing and the bendix. After rotating the starter by hand eventually I got it loosened up enough so it would spin decent off the motor. The crank was still acting weirdly locked up so I bolted the starter back on, put my tools up and offered the guy $20 which he took.

 

Also, don't run the pee out of the starter unloaded. I can imagine flinging the windings right out of the rotor from over revving the thing with no load on it. Just hit it with 12v for a second or 2. It will be obvious if the starter motor is working properly or not.

 

AND, anything made in china is prone to be bad right out of the box. Nixon was an idiot.

 

I had an old IHC truck that did that. It turns out the battery post had cracked away from the plates internally. It showed full charge with multimeter, but then the internal resistance wouldn't let the starter crank. If I wiggled the post (I think it was +) while somebody turned the key it would go.

New-ish battery.

If you haven't done this already, I would try putting a load on the battery and see if the voltage holds up.

Hang in there, partner; we'll crack this rock eventually.

 

was just out at JD's place.. talked to the guru that gave me the wirin specs the other day after I found out the price of the IGN switch module .. yup.. this one is mounted on a printed circuit board.. JD wants over 120$$ for it.. anyway the guru & I come up with addin a couple NEW grounds from the battery to frame & engine.. this was my hunch as Y the starters didn't spin..

 

well.. addin the new grounds didn't help with makin the starter spin.. & add to that I burned up my lil test push button switch.. so to replace it I have a spade terminal on both ends of a wire.. one on the solenoid & touch the other on the + of battery.. so as I stand now..I have found out the following::

1. seat switch is good
2. tranny nuetral switch is good..
3. battery is good.. purchased new 04-15-2015 & has 12.93 volts in it.. (spare test battery has 12.62 volts..)
4. both starters (old & new one) will spin when hooked to test battery..
5. both starters will (when mounted on engine & usin test wire to engage) will raise the gear to flywheel but will not spin.. this is even this way with new grounds..
6. I do not wanna spend anymore money on JD's crazy printed circuitry stuff..
7. this mower has a battery lite that comes on when u turn on the key.. I have found out that this lite will not come on if u have a battery charger just hooked to the battery (& not chargin the battery)

 

Make sure there is 12v leaving the solenoid and going to the brushes when you energize the solenoid while mounted on the motor. I'm running out of ideas. It would be nice if you could rig up a way to pull start the motor. Everything's pointing to internal engine damage or something external like the PTO clutch or some part of the td belt train or tranny.

I am not at all familiar with the Kaw singles and their ign. Are they simple AC magneto or DC CDI ?

 

can't check the output of the solenoid as it is mounted on the starter.. the Kohlers used on the first STX machines had a starter just like these.. there is no internal damage to this engine.. I can turn it over with one finger.. can feel the pressure of a valve opening & when it hits compression..

ign is simple AC magneto with a short out wire for stoppin engine..

 

I've come up with a new test to do..since I've been usin a test battery to test the starters.. I will hook it to the new starter (mounted on the engine) only (at the solenoid).. there will b no battery on the mower.. yet the key will b on.. the neg of the test battery will b grounded to engine block.. the POSitive will go to the solenoid only.. then usin my double spade jumper to the solenoid control wire.. & the other end to the test battery POS .. I will have a full charge on this battery..

doin this will not b sendin any 12 volt to the wiring harness.. no safety's or IGN switch to worry about.. just to see if the engine will turn over..

more info later..

 

Starter mounted solenoids have 2 large studs on the bottom. One is for the battery positive connection and the other energizes the brushes when the solenoid is activated by the small connector.

When you remove the small wire off the solenoid spade terminal and hook your remote starter switch to this terminal you have just removed the entire chassis wiring harness from the starter equation. Your coil kill wire will still be controlled by the chassis harness. Disconnecting the kill wire from the coil only leaves the antifire solenoid if so equipped.

 

u r so right .. this is what I wanted.. & the one bottom stud on the solenoid that goes to the starter is a covered one .. no access to check voltage there..

now then too I didn't want the engine to start.. just turn over.. this is Y I didn't feed 12 volts to the carb solenoid..

 

OK.. new info.. in the first pic u will see the starter spinnin the engine over real easy.. when I was hookin up the test battery I again noticed a repair done by a PO.. that repair is on the main hot feed to the mower.. it connects to male/female connector & thro a brown (real thin) wire it again has a taped connection at the wiring harness..

this repair is my prob I'm thinkin now.. I'm gonna open the harness where it connects & splice in a bigger wire straight to the battery terminal.. then see if all my headaches leave the wiring..

 

I went back up to my shop & did the repair thingy.. added in a piece of 12 gauge wire.. when I got it opened up some it looked like the end of a fuseable link.. this is a fuse that loks like a wire.. I think they blew it & for the repair they just wrapped the brown wire around the red one 1 1/2 turns.. no connector.. no crimp splice.. just a Micky Mouse repair.. I uploaded a before & after pic..

with evey thing hooked as it should b.. I tried to start the engine with the key.. all I herd was a loud .. KA..THUNK.. the starter gear hit the flywheel & didn't spin.. darn.. back to square 1.. voltage in battery was 12.43.. the test battery had 12.44 when it spun the flywheel a lil ago.. I also had a second NEW ground hooked to the engine

 

OK.. just went back to shop.. had to check the voltage I was gettin on the lil spade to the solenoid .. earlier I had reported this as 1.15 & 1.2 volts.. it is now at 12.42 volts when I turn the key to start.. I also noticed sumthin funny.. with key off.. 0.00 to solenoid small terminal.. turn the key to ON.. it reads 0.02 volts.. WTF.. am I gettin any bleed over from sumthin..

 

been thinkin on buildin a new wirin harness for the LX 172.. got a lot of it ironed out.. just the chargin circut remains.. I wanna use the present one on the LX.. will b usin a IGN switch from a STX that looks & mounts in the hole like the old one does.... then too a different PTO switch & different seat switch too... I used the followin stats for the new wirin..

1. with operator on seat it will have to start..engage the PTO & move in gear..
2. with operator off seat.. parkin brake on.. PTO off.. & in Neutral.. it will have to start..
3. with operator on the seat.. PTO on.. engine will kill if the operator leaves the seat..

check it over & see if it will work..

on edit.. forgot the followin info.. the IGN switch has continutity
in off position.. terminal 5 & 6
in on position.. terminals 1 & 3
in start position.. terminals 1 & 3 & then 2 & 4 for the start circut

 

Is this helpful?

 

YES.. in a way.. the area inside the dotted line of what u posted is the key switch module.. I think this one went bad.. & JD wants over 130$$ for it.. it has a new key switch & printed circut stuff attached to the switch.. I am wantin to replace it with a simpler one.. that does the same job.. & usin components that I have on hand..

 

well.. later today I will b usin the diagram to make the new harness.. & hook it up to the tractor after I disable the original harness.. so I can check out my drawing.. there is a new starter & solenoid on the engine.. with the old harness I can only get the solenoid to raise the starter gear to the flywheel but doesn't spin it.. with the printed circuitry stuff..

I find JD used a fuse link (which was blown at some time & then jumpered with a real light wire with just twisted together & taped.. JD also used 2 spade fuses in theirs..

if my test harness get's the starter to spin I think I can keep the oil & battery light that is on the machine.. & use the same rectifier/regulator for the 12 volt chargin.. this part is my next challenge..

my plan is to use as much of the old harness as I can.. (neutral safety.. seat switch.. & the likes.. just splice in my changes where needed & install the components)

when JD made the STX machines they were dubbed.. Suburban Tractor eXperimental .. then also the LX series was called Lawn eXperimental .. an improved model of the STX & Sabre..

 

The stuff inside the dotted border is all just passive stuff. No 'computer' near as I can tell. If you can solder, it can be fixed cheaply.

Just saying...

 

ur right on the 'puter part' but there is diodes & resistors & a couple small relays that u can't see how they r wired in the printed circuitry.. & also makes it hard to test when I do not have the proper specks of the parts there..

when I get done I hope that the cosmetic appearance of the machine is not changed.. even tho some parts r changed to meet a different type of circuitry..

 

Buddy,

Could you send me the board? I would like to look at it.

Pal

 

I could do that when I'm done with it.. it's got a ton of wires hooked to it.. I saw ur postin of a very expensive IGN switch assembly.. once I get all the connections made I won't b usin a switch like u posted..but the one I'm usin .. uses the same key & mounts just like the old one..

 

Ebay listing

 

Here's a used one for cheaper... Ebay

 

since I cut the original harness that one will not work..

 

spent the day fussin with this.. took the wire cutter to the original harness to hook up the one I drew up.. when I turn the key on.. I can hear the fuel solenoid operate.. turned it to start & all it did was raised the starter gear into the flywheel BUT did not spin the starter..

next I took the battery out & set it on the floor.. hooked 2 big cables to starter & the engine block.. then put a lil 12 gauge jumper on the spade terminal of the starter solenoid & touched the other end of it on the + battery terminal.. that starter spun over the flywheel.. this ruled out a 2 month old battery being called BAD..

put that battery back in the mower & hooked it up.. the starter end too.. then turned the key on.. raised the throttle to choke.. & turned the key to start.. I'll b go to h e double toothpicks.. that engine turned over & started.. let it run a minute .. turned it off.. 10 seconds later turned the key to start & she did.. ran nice.. did this 5-6 times & she started each time.. let it stay off a couple minutes & tried to start... NOPE.. she wouldn't.. starter gear hit's & engages the flywheel but no rotation.. checked battery voltage.. 12.65.. OK.. what gives with this..

 

Put a starter relay kit on it,might be what it needs

 

what good will that do other than make more connections,, as it is now.. the 12 volt for the starter solenoid comes from the IGN switch.. to the tranny neutral switch & thro the PTO switch.. (tranny has to b in neutral & PTO has to b off).. this is all 14 gauge wire so there shouldn't b any voltage drop.. (JD put in the 14 gauge wire when mower was made)

I tested the neutral switch.. seat switch.. the PTO switch & the IGN switch by havin them hooked to my multimeter & they were operated 50 times each item.. tested great..

I still don't understand Y the starter solenoid will raise the gear into the flywheel but it doesn't make the starter spin.. well it did 6 times.. & now doesn't..

on edit.. I have bench tested the starter & solenoid as they r mounted together as a unit.. also did bench test with starter mounted on engine.. it will spin it then..