Rz4619 can't keep the belt on. any help?

Safety and Preparation Serious injury can occur if the engine or mower blades accidentally start while you are working with lawn tractors. To prevent this, drive the Murray lawn tractor onto a flat work surface and disengage the mowing deck cutting blades. Engage the parking brake to keep the mower from moving; chock the wheels with a wooden block or brick. Adjust the mowing deck to the lowest position. Turn off the engine and remove the key from the ignition. While not necessary, you may even wish to disconnect the spark plug wire from the spark plug. Mowing Deck Removal You must remove the mowing deck on a Murray lawn tractor to gain access to the belts. Remove the adjustment rod hairpins, followed by the adjustment rod pins from the front left and right sides of the mowing deck. At the rear on the left and right sides, pull out the retaining hairpins and slide the mowing deck suspension links from the adjuster plates to separate the rear mowing deck from the frame. Remove the blade control rod stud, including the hairpin and washer, from the top of the blade control lever shift linkage at the left rear of the deck. Remove the front hanger rod, including the hairpin and flat washer that hold the rod in place. Loosen the belt guide retaining bolts with a socket wrench and remove the engine stack pulley belt so you can slide the mower deck out from under the tractor Transmission Drive Belt Installation Slide the new transmission drive belt between the engine stack pulley belt guides, over the belt guide plate and under the engine stack pulley. Fit the transmission drive belt around the top engine stack pulley. Push the free end of the transmission drive belt up through the transmission shifter hole in the lawn tractor floorboard. Slip the transmission drive belt loop over the transmission shifter. Pull the transmission drive belt down through the transmission shifter hole. Fit the transmission drive belt around the transmission drive pulley and tighten the transmission drive pulley belt guide retaining bolts to hold it in place. Fit the transmission drive belt flat side around the idler pulley. Slide the idler pulley onto the idler pulley stud while holding the belt in place. Tighten the transmission idler pulley retaining nut with a socket wrench to secure the idler pulley to the idler pulley stud. Mowing Deck Drive Belt Installation Pull back on the right side mowing deck mandrel pulley spring-tensioned belt retainer. Guide the new mowing deck drive belt around the right side mandrel pulley and release the belt retainer. Pull the drive belt spring-tensioned retainer away from the mowing deck idler pulley, guiding the deck drive belt around the idler pulley. Fit the mowing deck drive belt around the left side mandrel pulley and under the rear mowing deck cross link rod between the right and left side mandrel pulley. Slide the mowing deck under the right side lawn tractor frame, reconnecting the deck to the frame in reverse order of removal. Engage and disengage the mower deck while driving the mower to test the belt for proper operation.

Sounds like a spindle bearing out

Did the smoking stop when you disengaged the blades? If so it is most likely your belt that is smoking. Make sure all the blades turn freely by hand to ensure you have not hit anything that may have bent a shaft on one of the blades. If one of the shafts is bent and wont turn FREELY, the belt driving the blades would slip and start smoking as it tried to turn them.

Wearing out a belt that fast must have a bad bearing or a misaligned pulley. Good luck.

Hi, check your belt tension, check all idler pulleys and drive pulleys for free rotation with the belt off and finally check that the belt is not bottoming out in any of the drive pulleys. If so, replace the belt. The blades should come up to speed imediately wether hot or cold and it sounds like your belt is slipping in one or more of the pulleys which drags the motor revs down until it grips. Regards Phil.

You either have a bad bearing on one of the pulleys or one is loose and moving up and down drawing the belt when it is engaged. I would pull the mower deck off and go through it .

This 1991-92 model is equipped with a blade brake clutch. When the blade slows down this means the belt is slipping. This slipping can be caused from a few different things.
1 --A loose cable.
Try adjusting the blade cable on the upper handle. this unit has an adjustable section. make sure the cable is not so tight that you snap it.
2 --A sticky pivot point under the belt cover
The belt cover in the back builds up with dirt and debris. Make sude it is clean under the cover and all of the pivots move freely. ( do this with the engine off)
3 --A sticky belt tensioner under the deck cover
The underside of this machine has a metal cover to protect the belts. Remove it and check that the blade belt idler arm is not frozen in place. this will cause the belt not to enguage all the way.
4 --A worn belt or belt pulley
The large flywheel and pulley can wear. Check this if the belt looks good.
This is all there is to the machine BBC system.
I hope this helps.

Get parts and more diagrams at a Master Toro Dealer like www.arcolawn.com

Is there the proper amount of tension on the belt?Look in your owner's manual to find out how to adjust the tension.

The belt hopped off likely due to grass or other things getting in-between the belt and pulley near the blade. You should be able to remove the cover on the top of the mower deck, remove the belt from the pulley under the cover, place the belt back on the pulley near the blade and then on the pulley under the cover. If the belt is shiny on the sides or you see black powder caking the inside of the cover or area's around the pulleys or the belt looks like it has chunks missing from any part of it the belt should be replaced. local hardwares, automotive and DIY centers that carry outdoor power equipment parts can match it up with the one the manual recommends using.

Tip: Keep the blade sharp, I recommend buying a couple blades so that you can always have a sharp spare installed while the other is being sharpened, change the blade as soon as the sharp edge is gone and becomes somewhat rounded on the cutting edge. If the lawn produces a lot of dust or there are lots of bald patches this will dull the blade quickly as will chopping up stick with the mower, if this is the case take steps to improve the lawn and keep the sticks picked up before you mow.
Change the oil before using it in the spring and after each 50 hours of use (more often if its used in a dusty area).
I recommend using a synthetic oil unless the manual specifically states not to.
When mulching mow in counter clockwise circles, when bagging mow in clockwise circles and in either case overlap about 1/4 the width of the mower for a complete smooth cut. after each mowing allow the mower to cool then tilt the mower on its side opposite of the carburetor (where the air filter is) and wash off the stuff stuck to the bottom, you may have to use a putty knife on the real thick or stubborn stuff. This will reduce corrosion over the years and keep the mower running and mowing efficiently not mention it avoids blowing into the air backteria produced as the clippings of past mowing decay (it makes me sneeze).