Here are some specs for comparison. Some manufactures provide Gross HP figures at the flywheel, some net, some both:
The folllowing are JD Models: Gross HP, Net HP, PTO HP, # of cylinders, disp in cu. in., trans gears forward/reverse, weight for 4 wheel drive models. They all offered 4 wheel drive at one time:
670 19.3 18.5 16 3 53.6 8/2 1,860
755 21 20 15 3 53.6 Hydro 2 range 1,835
770 25.5 24 20 3 83.1 8/2 2,105
855 24.9 24 19 3 60.7 Hydro 2 range 1,870
870 28.7 28 25 3 87.3 9/3 2,760
955 35.3 33 27 3 87.3 Hydro 2 range 1,990
970 35 33 30 4 110.8 9/3 3,045
1070 40.9 38.5 35 4 116.3 9/3 3,265
Although the 55 series engines are putting out more HP per cu. in, they typically do it in the 3,200 rpm range vs 2,600 rpm range. for the 70 series. Those tractors are of a new design and are definately lighter in weight than the 70 (now 90 series)
I currently own a 770 4 X 4 and have been running a 4 ft LX4 rotary cutter. I've cut stuff higher than the stack with no problem and no bogging down. I probably could drive a 5' as the guy I bought this from did use a 5'. Mine is a 1998, the last year for a 770. They were replaced by the essentially the same 790, only with 5 more HP accross the board. Mine had 230 hours on it and I've added 25. It's a great, tough little "basic" tractor, built in Japan by Yanmar.
If you want me to, I can copy the brochure for the above models and mail it to you. Send me an E-mail. Sorry the numbers are jumbled up and hard to read, they were in neat columns when I posted it.
Hope this info helps. I was able to find a catalogue at the dealer, but I had to ask for it and they dug it out of their files.
Joe
