My Craftsman riding mower runs fine but when I try to cut thick or tall grass the blades slow down and stop cuting, I replaced the belt thinking the belt was worn only to find I still have the same problem, I also have problems getting the blades to start when the handle is engaged I have to engage and disengage the handle two or three times to get the blades to start, Is this a tensioner pully problem ?

if it is an older mower or has a lot of hours on it it is possible that the deck belts have stretched or wore out. if it runs fine in short grass but slows down in taller grass that is a sign of a wore belt. replace and it should be good. also be sure your blades are sharp. that will have a effect on its cutting capability.

sometimes when a belt is wore out it will let the tall grass stop the blades from spinning. put on a new belt and should be good.

your belt is slipping. Have your dealer fix it.

Some self-propelled mowers include a speed control, but sometimes it may seem that no matter how you adjust it, the mower just creeps along at a snail's pace. Most likely this isn't a mechanical malfunction, but an adjustment is probably needed.

Very tall or thick grass can bog down a self-propelled mower, but adjusting the height of the blade may allow it to roll through and cut the grass at normal speeds. If the blade is low, the amount of cutting required may slow down the movement of the entire mower. The frame of the mower may also stick in the high grass. Raise the blade little by little until the mower rolls at the appropriate speed. Going up hills may cause a similar response.

It's possible the drive belt on the mower can slip. Inspect this part to see if it is loose or cracked, and replace the belt to restore power.

Hello,

The reason the blade slows down when the grass gets thick is simply because the mechanism operating the blade is weak and cannot move fast when on thick grass.

I suggest you troubleshoot the mower. After that, the blade should work fine when the grass gets thick.

Also, some mowers normally gets slow when grass gets thick, so after troubleshooting, if the mower does the same, then you already know it has to be slow when trying to cut thick grasses.

Take care

If the grass is very tall (more than 10") you will have to slow down to less than 1 mph, if you have a mulch kit on this unit, remove it to get the grass out as quickly as possible. Also, sharp blades & a level deck are important.

You mention many PM issues but do not mention a blade sharpening. I don't get on my ZTR without a freshly honed blade installed. "That's" what cuts bahia grass...the blade. You can put all the horsepower you want behind the lade but if you're trying to cut grass with a 2X4 it rips more than cuts grass.

I've noticed that when the blade get dull it work harder a cutting tall grass. I just put a new blade on mine and now it runs and sounds like a brand new mower. also if the inside of the deck is coated with old grass that makes a differance too

Most likely what you did was burn one or more spots on the belt. When the blades and belt stop turning, like in tall grass, the engine doesn't stop and will burn flat spots on the belt at the engine pulley. Every time the flat spot hits a pulley, it will jump and can set up a bad vibration. Run your hand around the sides of the belt or take it off and you will feel or see the thin spot(s) on it. Replace belt.

13 to 15 amps electric or battery operated mower may runs slow when cutting thick grass. also recommended not to cut grass when it's wet & need very sharp blade to do the lawn. may overloading it, cutting grass too thick also draws too much power. check house breaker first.