Jim,
Thanks for your thoughts as always.
I'd still be tempted to run kerosene using the jet for diesel, but that's me.
If it were me, and I were going into an area where I'd be in a real fix if my stove weren't working, I'd bring both pumps. The pump is definitely the Achilles heel of MSR liquid fueled stoves. A spare pump, particularly if you're traveling by vehicle or something where weight isn't quite as critical, is peace of mind, as is an expedition service kit. I don't always travel with two pumps and a full service kit, particularly for backpacking, but if all the weight isn't on your back, why not carry the "insurance?"
Can you imagine lugging something as big and as heavy as a 111 up the side of a mountain. It's that good. There were mountaineers who were willing to lug the beast up the face of a peak simply because the 111 was such a good stove.
HJ
I have only run kerosene once, on Spitzbergen, in my old XGK. I almost always use AvGas or Jet Fuel, taken from the aircraft that brought me into an area, if I don't have white gas. The biggest advantage is that I can put it back in their tanks when I leave and not have to worry about how to dispose of it in a hotel or airport when I return home (usually by air).
I have regularly carried an enhanced service kit and a spare pump when I was not backpacking. Of course when I was backpacking, I mostly carried my 123!
Even in mountaineering, the pump is critical and I carried a spare.
Not only can I imagine packing a 111, I have done it several times. That is how I ended up with an XGK, I loved the 111 for cooking and melting snow, but not for carrying.
In the 60's I borrowed several stoves for use in the mountains. I had a 111b on my purchase list when I saw an XGK. It was great for the mountains, super for fly in camps, and OK for canoeing (no simmer and I do LOVE my pancakes and banock when canoeing). The 123 was for day trips and backpacking where fuel was easy to get (at home). Sometimes I took both canoeing if the portage length was not too great and I expected to be able to get white gas.
Thanks again,
Jerry