Hi,was rolling my lawn with a yth2454 husqvarna.i released then pushed on drive pedal and it wont move.i replace the motion belt now it moves but barely.the old belt was stretched.also now there is a sqreeching noise coming from the engine pulley/clutch area?

so is a
Husqvarna YTH22V46 22-HP V-twin Hydrostatic 46-in Riding Lawn Mower

this is real name, and is mower not a car.
moved yah

jack it up and wiggle rear tires to free up box ?
brakes set?

Question edited for clarity, spelling of maker and full 'make model (what it is)'.
Question moved from Cars and Trucks category.

They all have some way to adjust the tension of the drive belt.

https://www.google.com/search?q=Husqvarna+YTH18542+adjust+belt+tension

Belt Routing.

https://www.google.com/search?q=husqvarna+yth18542+belt+routing+diagram

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look under unit follow pedal and look for return spring -if disconnected or broken repair or replace as necessary-look for debris stuck in area

Which belt? The cutting deck belt or the belt which drives the mower?

i had a 2148. you remove the mower deck as the first step. feed the belt over the pulley on top the transmission, then put it over the engine pulley. then have someone push the clutch pedal in so the tensioner pulley moves, put the belt in the guide pulley and on the tensioner. release the clutch put the deck back on and you are good to go. notice there are little keepers welded to the frame for the front, engine, pulley and it is easy to mistakenly put the belt over them instead of under them.

a general rule is that a pulley shaped like a Vee takes the V of the belt whilst a pulley which is flat takes the flat back of the belt. if you bear that in mind you will not have a problem putting belts back on. also there is a little decal on top the deck showing how the deck belt and deck drive belt go.

Check to see if your drive belt has slipped off the pulley assembly, or if you have broken a pulley or the belt itself broke.

It sounds like the transmission drive belt is slipping. When you pull the pedal back you are increasing the tension on the belt. You may also want to make sure the spring that pulls tension on the idler pulley is in tact. Hope this gets you in the right direction.

When you raise the front or rear of the tractor, and push on the belt (engine off of course), is there a lot of play or slack in the drive belt. At this point from what I have read, the issue is the drive belt, and is slipping when in gear and when it heats up. The next thing to do would be to replace the belt, but I not sure if this procedure is an option for you. When you inspect the under side of the tractor, and inspect the moving parts and pulleys, if any of these components are in need of replacement, you will be able to tell by either rotating them manually or visually inspecting them. At this point due to the low hours, I suspect the drive belt is stretched out, and is considered a maintenance replacement part procedure.

sounds like you sheared a woodruff key check the key on the pulley. Or maybe your belt is no good or came off the tension pulley anyway that might get you in the right direction.