The manual for my L2500DT says to warm it up for 5 minutes with
no load, and then 10 to 30 minutes or more before applying
full load, depending on ambient temperature.
My baby sleeps indoors, however, so I fire it up, wait
30 seconds (just to be better than GlueGuy /w3tcompact/icons/wink.gif) before raising the FEL and 3pt implement. I then ease her just out into the open and set the brake. Then, before I hop off, I set the throttle to about 1,000 rpm, as also recommended by the manual, for the rest of the warmup.
I putter around for about 5 minutes or so, by which time the temperature guage is just about at half scale. That's the normal operating temperature for my 'Bota, but as we've discussed in other threads, many guages barely register anything at operating temp.
On a side note here -- the manual also says to pre-heat the engine glow plug thingy for 20 to 60 seconds (depending on ambient temp) before cranking it up. The dealer (and they're never wrong, are they?) said that wasn't really necessary in our California climate, so I never have. The coldest air temperature I've ever tried to start up in was about 38 degrees F, and, like always, it fired up instantly.
So tell me, mechanic dudes -- are there other reasons than fast starting for preheating? Am I damaging the engine with my cavalier approach? /w3tcompact/icons/crazy.gif