cub cadet 1050 will not crank when warm

[josie]

My father bought a Cub Cadet 1050 about 2 months ago. Ever since he got it he has been having trouble with it not starting after it is warmed up. After running for an hour or so if he shuts it off for a few minutes it will not crank over when he tries to restart it. The solenoid does click so I don't believe any of the safety features are preventing it from starting. He has sent it back to the dealer he bought it from several times and they are now telling him that they can't duplicate the problem and that it is "operator error". My father is a very mechanically minded person (he is a former jet engine mechanic) and I'm sure this is not "operator error" He is very frustrated with the "new" machine he just bought.

So far the dealer has done the following

• checked safety switches
• replaced starter
• checked battery cables
• replaced battery twice

I have searched and can't seem to find anyone with this same problem. Anyone have any ideas?

 

[rcbe]

when it won't start again: remove air cleaner. have assistant attempt to start engine normally (in seat, 1/2 throttle, PTO off, cl/br pedal fully depressed). Spray several shots of carb cleaner directly down carb throat ( NO ether starting fluid !!).
If engine pops or tries to start, you have a fuel delivery problem of some type. If not, there is an ignition or mechanical problem. Note info and re-contact dealer to have fixed. Involve CC Area Service Supervisor if required.

 

[justme23005]

Is the solenoid mounted on the starter? Its pretty easy to troubleshoot. if its clicking, you are getting voltage to the solenoid. using a test light, see if the voltage is going through the solenoid, to the starter. Make sure the starter is grounded properly. I'm guessing that your solenoid is bad.

 

[jim44]

My 1050 used to do that when hot--acted like the battery was weak. Finally figured out that it was just a compression thang. If it happened to stop just as one cylinder was coming up on the compression stroke, the starter had a hard time kicking it over. Found that just bumping it (the starter) a few times, it would finally get past the compression and be good to go. The problem lessened as the mower aged (gracefully, of course).

 

[JRobyn]

I feel his frustration! Please explain exactly what the starter motor is doing/not. Does it turn any? Can you hear the starter drive gear engage the engine flywheel (clank)? Does it crank the engine over "normally" but with no start? Can we assume that this is the Kohler twin cyl engine? What HP?

If I understand correctly so far, the solenoid is engaging (it is external, mounted up along the steering column), but the starter motor itself is then doing NOTHING, right? According to the schematic for my older 1050, there should be no electrical devices between the solenoid and starter other than the big red wire. All the safety switches are in the "control" part of the circuit. You can verify for yours if you get a schematic from MTD with your exact model and serial number. It is in the back of the PARTS manual.

If all of that (so far) is true, then the problem almost has to be either with the solenoid itself (coil is energizing so you hear it click, but something is bad with the high-amp starter wire or contacts). Or with the actual starter. You can test the starter motor while it is hot, by just connecting a high-amperage wire (jumper cable) directly from the battery + to the terminal on the starter.

There's a small chance that there's a problem with the ground path, so be sure that the starter motor mount bolts are tight and that any engine and battery ground straps are good.

- Jay

 

[Gator6x4]

Find the wire coming from the ignition switch to the starter. It should be a small wire that clips onto a prong on the starter solenoid. It should read 12 or more volts when the switch is turned to the start position. If 12 or more volts reading is not received, the ignition switch is not sending enough voltage to the starter after it gets hot to start the engine.

You can also use a jumper wire and apply battery voltage to the prong and see if the starter will engage and spin the engine over. PLEASE DO NOT HOOK A 12 VOLT JUMPER WIRE DIRECTLY TO THE STARTER SOLENOID. YOU WILL DAMAGE THE SOLENOID AND COULD HAVE A FIRE.

If the ignition switch is not sending the correct voltage to the solenoid, you can wire a relay into the starter circuit and the starter will then spin the engine each time the switch is turned to the start position.

 

[OldMachinist]

This was a common problem on many MTD built mowers. The power to the starter relay runs thru all the safety switches before it goes to the starter relay. One of the switches likely has high resistance when warm and is reducing the voltage to the starter relay. The cure recommended by MTD was to add a relay to the system. Here's the wiring diagram from MTD for adding the relay.
Starter relay wiring

 

[Jack Vines]

X2 on this one. The wiring is failing him and will continue to do so. As mentioned, the start and run circuits go through the brake pedal, seat, reverse and the PTO switch. They will all eventually fail in one mode or another. I tried buying the very expensive OEM replacement switches, but the eventual cure was to remove them all and rewire the machine with only a quality aftermarket start and PTO off-on.

If your father is a former jet engine mechanic, the rewiring should be well within his capabilities.

jack vines

 

[josie]

Thanks for all of the suggestions. I can't answer a lot of your questions since I have not witnessed the problem. He lives about 50 minutes away and I haven't had a chance to get up there. The dealer has agreed to send a mechanic to his house to witness the problem. We'll see how that goes. Although he is capable of troubleshooting this problem he's 80 years old and feels that this is an issue that should be handled by the dealer under warranty. I'll let you know how things go.

 

[Jack Vines]

Warranty, what a unique concept. Since I've always bought my CCs used, after the original owner gave up trying to keep them starting/running, I've never had the pleasure of just calling the dealer.

Yes, two months is definitely something the dealer should handle. However, as previously mentioned, just because it will be fixed for this summer doesn't mean the switches and wiring won't be a problem in subsequent years.

jack vines