John deer selp propelled blades don't rotate fast enough to cut the grass

SOURCE: lawn mower belt diagram

try www.johndeere.com apply for user id and password

will need to wait for these to be issued to you via e-mail

then go to www.jdparts.com and enter your user id and pw and enter the correct site for your country and then enter model stx38
scroll through list to find deck or attachments and double click it

your deck could be a yellow or black deck


cheers

SOURCE: I need a belt routing diagram for a John Deere

If you go to this page http://manuals.deere.com/cceomview/OMGX21647_K3/Output/Index.html?tM=HO , scroll down the left side to the heading for your deck.

SOURCE: I replaced the belt on the lawn mower the idler

look up john deere web site for spare parts
print out parts cataloge for parts , it gives you the basic outline and shape of belt configeration