Bush Hog CZ2149 zero surn mower shutting off...why?

[tracecom]

I have a Bush Hog CZ2149 zero turn mower with a Kawasaki 21hp engine; the mower has 240 hours on it accumulated over the last six years since I bought it new.

Last year, I began to experience shut downs. While mowing along, the engine would suddenly quit as if the fuel had been shut off. After turning off the switch, the PTO, and setting the parking brake, the engine would restart normally, and continue to run sometimes for hours, and sometimes for only a few minutes.

I replaced the fuel filter and the fuel pump. No improvement, but the shutdowns were infrequent enough that I put up with the problem for the rest of last year.

This year, I mowed twice with it (about 6 hours, total) and had no problems. Then, on the third use, the problem became intolerable. The engine might run 15 minutes before shutting down and it might run less than a minute. Restart continued to be flawless.

I shorted out the seat switch: no change. I replaced the PTO switch: no change. I replaced the control lever switches: no change. I tested the parking brake switch: works properly.

Something is apparently interrupting power or ground to the fuel solenoid on the carb just long enough for the solenoid to release. Then, of course, the safety switches keep it from retracting until the start up sequence begins again.

Now, I am considering replacing the keyswitch, but it's just a blind shot.

If someone has experience with this issue, I would love to hear about it. I have worked with the dealer and he's mystified, and Bush Hog tech support hasn't returned my calls.

Thanks.

 

[MoKelly]

How frustrating.

I don't have your machine, but I had a similar issue with my Gravely. I would be mowing and the machine would just stop. Turns out it was my brake. If I hit a bumpy patch or went too fast the brake would bounce up enough to shut off the engine ... but not be enough for me to feel the drag. Then, like you, I could easily restart from scratch.

I tightened the brake and now every once in a while push down on the brake while mowing. It hasn't been a problem since.

Good luck.

MoKelly

 

[LFEngineering]

Can you jump / override the fuel solenoid and see if the problem continues? Also does the motor have a oil pressure or oil level shut-down switch?
Also now that it's happening at more frequent intervals could you try to keep it running via starting fluid, if so you can narrow down if its fuel delivery or an electrical shut down.

 

[tracecom]

How frustrating.

I don't have your machine, but I had a similar issue with my Gravely. I would be mowing and the machine would just stop. Turns out it was my brake. If I hit a bumpy patch or went too fast the brake would bounce up enough to shut off the engine ... but not be enough for me to feel the drag. Then, like you, I could easily restart from scratch.

I tightened the brake and now every once in a while push down on the brake while mowing. It hasn't been a problem since.

Good luck.

MoKelly

There have been times when I hit a dip and the engine would rev down as if it was going to stop, but it didn't. Now, it does seem to stop sometimes after a bump, but not always. The only brake on the CZ2149 is the parking brake, but I will check it out.

Thanks for your input.

 

[tracecom]

Can you jump / override the fuel solenoid and see if the problem continues? Also does the motor have a oil pressure or oil level shut-down switch?

I hadn't thought of overriding the fuel solenoid, but it's worth a try. I would need to find out for sure what the operating voltage is (12V, I guess) and then wire the solenoid directly. Of course that would mean the engine would probably backfire when I shut it off. I suppose I could wire a manual switch to the solenoid and use that switch to kill the engine. It's worth a try.

Yes, the engine does have LOS. And I have seen the LOS float stick to the bottom of the sump in engines that weren't used very often. I don't think LOS malfunction is the issue because the control panel has a low oil indicator light that works, and the light doesn't come on until after the engine stops.

Thanks for your input.

 

[tracecom]

The tech support guy from Bush Hog called, and suggested I look at the fuse block for corrosion. Beyond that, he just said electrical problems were hard to find.