Just bought a MTD 38 " 2nd hand .. the cutter belt was snapped when purchased ... Manual says 77 7/8" belt..
I fitted a Kevlar belt, 76" internal = 78" OD ( 3mm bigger than official belt).. it was WAY too loose!...
I then fitted a 75" ID belt which actually worked out at around 76.5" OD, when measured, which is a fair jump in down sizing.. That one was definitely a wee bit smaller than the old snapped belt when compared..
However it STILL seems too loose... As soon as I started up the cutter system, the belt flaps from side to side as shown in linked video file 1, enough to put vibration through the whole mower and even makes the bonnet flap a bit ...also when stopped, but tension still on,, it is quite easy to push in with a finger....as shown in vid2
While collecting belt at mowershop, i had a look at the tension on the display Rover/MTD mowers that were nearly identical design wise.
When i engaged the cutter belt on these new machines, their cutter belts were definitely tighter than mine even with the new smaller belt..
When fitting the belt it easily fitted over the front drive pulley .. one size smaller I think would still juuuust fit over without straining at it....
Should I go to another inch size down perhaps? loathe to spent another $40 for another belt, but no point flogging the mower out with a too loose belt...
Edited by humpy, February 02, 2018 - 03:55 AM.