Went to give the mower a servicing and the starter solenoid got stuck. After finally getting the starter to stop replaced the solenoid. That’s when the problem began. Started just fine and ran about 5 minutes then went dead checked fuel ,getting fuel checked spark, no spark. Pulled kill wire off coils now have spark but the mower now is very sluggish and using twice the amount of gas. Tried tracing the kill wire but have had little success. Any helpful advice and suggestions will be much appreciated.
Z121s giving me fits.
- Thread starter Ole Yeller
- Start date
The kill wire runs up under the engine's blower housing.
"Kohler".
"usually" on those, if you lose spark because of defective wiring or switch or whatever, it'll lose spark on BOTH. The kill wire is connected in series to both modules (aka coils).
Now with that said, if you're losing one cylinder (which I suspect you are), pull the blower housing off and see what kind of coils you have. If you have the 3 or 4 wire kind (which are DSAI coils), replace both of them with the new MDI kit, available from Kohler (part # 32 707 01-S) and I think also Kubota under a different part number of which I do not have handy. Kubota may be less expensive so double check.. DSAI coils have/had a very high failure rate. If you have the single wire version, disconnect both kill wires, then start the engine. If it runs on both cylinders again, your coils are good and there is a wiring issue (grounded/shorted) somewhere.
if you have spark on both cylinders and it's using a ton of gas/low on power, check the throttle cable adjustment and make sure it's not choking. Also if ya ain't already, check the air filter make sure it ain't plugged up.
"Kohler".
"usually" on those, if you lose spark because of defective wiring or switch or whatever, it'll lose spark on BOTH. The kill wire is connected in series to both modules (aka coils).
Now with that said, if you're losing one cylinder (which I suspect you are), pull the blower housing off and see what kind of coils you have. If you have the 3 or 4 wire kind (which are DSAI coils), replace both of them with the new MDI kit, available from Kohler (part # 32 707 01-S) and I think also Kubota under a different part number of which I do not have handy. Kubota may be less expensive so double check.. DSAI coils have/had a very high failure rate. If you have the single wire version, disconnect both kill wires, then start the engine. If it runs on both cylinders again, your coils are good and there is a wiring issue (grounded/shorted) somewhere.
if you have spark on both cylinders and it's using a ton of gas/low on power, check the throttle cable adjustment and make sure it's not choking. Also if ya ain't already, check the air filter make sure it ain't plugged up.
You have a lot going on there! Hope you can solve your issue…maybe try YouTube and look for associated problems? People post all kinds of problems there…good luck!
I have the one wire coils but did not check both coils. It may be running on one cylinder like you suggest because the exhaust note is different. When the kill wire is installed in series it won’t start but if you unplug one it starts right up. Will check the coils to see if I’m getting spark on both. Throttle was the first thing I checked seemed in good working order.
If one coil's kill wire is still connected, and it's not running on that cylinder, the kill wire is probably grounded-somehow. That could be from a failing pto switch, brake switch, etc.
There are other possibilities but usually it's a switch or shorted to ground wiring that causes it.
There are other possibilities but usually it's a switch or shorted to ground wiring that causes it.
It’s been a month and I’m giving a update. The mower did have a bad coil so I have replaced both. But it still runs sluggish, changed plugs fuel filter. Still has power loss and excessive fuel consumption. I am wondering if it may have a blown head gasket or broke ring.
With a cold engine, pull one plug wire off. Then try to start it. Will it run? If not, the other cylinder (the one you left the plug wire on) is not running. Why? Fouled spark plug? Pushrod off? Broken rocker arm? Pulled rocker bolt? Carb dirty? Do a compression test. Should be 150+. If low, you'll have to investigate why-and if it is low on that side, pull the valve cover off and have a look-see.
Kohler engines seem to be ok. I wouldn't call them "great" but it's not common for them to have issues outside starters, UNLESS the air filter and/or engine oil is neglected. Or if they sit for long period. With that said, I've seen ONE of them (same mower) that a valve was sticking in it's guide, which allowed the pushrod to fall off, which then it wouldn't run on that cylinder. Only one-out of several hundred. But I felt it worth mentioning.
Kohler engines seem to be ok. I wouldn't call them "great" but it's not common for them to have issues outside starters, UNLESS the air filter and/or engine oil is neglected. Or if they sit for long period. With that said, I've seen ONE of them (same mower) that a valve was sticking in it's guide, which allowed the pushrod to fall off, which then it wouldn't run on that cylinder. Only one-out of several hundred. But I felt it worth mentioning.
It runs on either cylinder I also invertenly left the dipstick loose and had oil blowing everywhere. Is the crank case supposed to have a lot of pressure..
Daren Todd
Well-known member
Lifetime Member
Equipment
Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
Call your local dealers service department. Give them the serial number for your unit and have them check for recalls.
My Z121s had recalls for the safety switches as well as the belt tensioner.
Your issue may be covered and fixed for free.
My Z121s had recalls for the safety switches as well as the belt tensioner.
Your issue may be covered and fixed for free.