mrc 818 #1 Posted yesterday at 07:04 PM hello men, for over 30 years i have plowed with an eight speed. i recently picked up a workhorse 1848. the previous owner installed a kohler 10hp magnum engine. he told me the original twin cylinder engine blew up. the engine drive pulley is only 4 inch. so i installed a 5 inch pulley.. i believe that is necessary to spin the hydro fast enough. correct? i removed a dayton belt BP76. which i believe is a 5/8x79 inch belt. obviously because of the larger pulley i need a longer belt. what size? thank you in advance regards mike Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,070 #2 Posted yesterday at 07:40 PM Going from a 4" pulley to a 5" requires 2 " more belt so 5/8" x 81". The original belt with the twin cylinder engine was 5/8" x 83". A C-125 with same Eaton transmission used a 5/8" x 81.5" belt. I do not know the correct pulley diameter. Share this post Link to post Share on other sites
ri702bill 8,387 #3 Posted yesterday at 08:04 PM Mike - too many non OE variables. With a pair of extra hands, try threading a length of rope over the pulleys to get an approximate belt length. Buy 3 returnable belts - the rope length size, one an inch shorter, one an inch longer. Tractor Supply will accept returns if unused and in original sleeve, with the receipt. Been there, done that. 1 1 Share this post Link to post Share on other sites
kpinnc 12,174 #4 Posted yesterday at 08:47 PM 1 hour ago, mrc said: so i installed a 5 inch pulley.. i believe that is necessary to spin the hydro fast enough. correct? 5.25 but yes the hydro spins a little faster. Share this post Link to post Share on other sites
mrc 818 #5 Posted yesterday at 08:55 PM before installing the pulley i measured it. you are correct kpinnc it was 5.25 inches in diameter. i guess my first question is, is that the proper size pulley when running an eaton 1100 tranny? thank you mike Share this post Link to post Share on other sites
953 nut 55,393 #6 Posted 23 hours ago (edited) 3 hours ago, mrc said: is that the proper size pulley when running an eaton 1100 tranny? Yes it is the proper size pulley and a 5/8 by 82" belt should do the job. The circumference of the 4" pulley is about 12.6" and the 5 1/4" pulley has a 16.5" circumference, so the portion of the pulley being contacted by the belt increases by about two inches. Edited 22 hours ago by 953 nut Share this post Link to post Share on other sites
kpinnc 12,174 #7 Posted 21 hours ago 4 hours ago, mrc said: i guess my first question is, is that the proper size pulley when running an eaton 1100 tranny? Yes sir it is. Same for the Sundstrand hydro as well. Share this post Link to post Share on other sites
