No, do not force feed the engine anything. Bad stuff happens. If it won't start on it's own, find/fix the reason it won't.
On a diesel, you know you are getting fuel if during cranking the engine you see some fuel smoke (usually white, smells like diesel) coming out of the exhaust pipe. No smoke, no fuel-and it really is that simple.
On a diesel you need air, fuel, and compression. No spark needed. So if you're not seeing any fuel out of the exhaust, chances are good you found at least one issue...no fuel. But why? If it was run out of fuel at any point in it's recent life, you can add fresh diesel to the fuel tank, turn key on, and then bleed the injector pump. There is a bleed screw where the fuel line goes into the side of the pump. Loosen that screw (10mm hex?). If the electric fuel pump's working, fuel will begin to flow out of the bleed screw. Let it flow a few seconds, close it, and try cranking. Might take some cranking; but at some point if everything's correct, you should at the very least see some fuel smoke from the muffler outlet.
If when you loosen the bleeder, if no fuel runs out, then it could be a plugged filter (IIRC, there are two filters on the G2160's), or could be a failing electric fuel pump, or junk in the tank plugging the outlet.
If you get fuel smoke, but still not starting, check the air intake system for restriction. If good, could be low compression.
I used to own one of the G2160's and while I liked it for the most part, I hated the electric power steering and despised the rear discharge bagger which was useless for my needs. Couldn't find a side discharge for it, so I dumped it in favor of a G1900. Other than that, it was a good mower. And fast. I think it mowed at right around 12 mph if I remember right.
