In Reply to 4WD maximum speed ... (more) posted by Chris Myers (CMyers) on February 29, 2000 at 16:45:23
Now, I haven't tested this or anything, but somewhere in the manual or something I read that 4Low put either 3 or 4 times the amount of strain on the engine. Now it's crude, but I took the max speed of that(roughly 20MPH) and multiplied it by that 3 or 4, so 60 or 80 MPH, whether it be 3 or 4 times the strain.
I've run it up around 55-60 with no noticeable effects on the way to school in some odd weather.
Just my theory,
--Rich