Emergency Stop Rod / Cable / Lever / Knob

[Stubbyie]

I've been following earlier threads about engines that won't stop.

I realize some Kubotas and some other diesels are designed to be stopped using only mechanical decompression---"pull this knob to stop". Others use a key supposed to stop the engine.

We have one Kubota has key-only and another one has the key + pull to stop knob.

Question: why are both systems on some machines with "keyed" ignition switches? Is there an expectation the key switch will fail? What's the reasoning behind this setup?

The only other place I've ever noticed the decompression pull lever is on BIG diesels on drilling rigs. I was around one once that experienced a run-a-way when it got a sniff of natural gas. Engineman jumped and pulled a lever on each engine and they all shut down (for the purists, these were on the floor, the drawworks; not the pump engines down on the ground) while we sorted out which way to run.

But back to the question, is a run-a-way engine expected on a farm / construction site? Is a run-a-way the basis for this two-kill or is there something else behind the scenes?

I guess any key switch can fail, but how hard would it be to throttle back to idle and choke off fuel / air or just lug it down to kill it? Why have the key at all if this is the thinking?

I'm curious what the attendees of this forum think about this set-up on our tractors.

Thanks for your considered opinions and knowledge.

/s/Stub.

 

[cmorningstar01]

Both my Kubotas(B5100E & B7500HSD) are designed to be stopped using the manual fuel shut off and not decompression, On the B5100E there is a little lever that is connected to a linkage that connects to the injector pump, The B7500HSD has a knob that is pulled out this is connected again to the injector pump, The B5100E does have a seperate decompresion knob with a warning label that says not to use it to stop the engine, The B7500HSD does not have a decomp knob and does appear to have a decompression device at all.