Mower blade is spinning loose is not connected to motor. did a stud brake cause not is tight

Before you start removing covers and panels unplug the mower. Turn the mower over and carefully try to spin the blade by hand. Your checking to where the issue is most likely to be.
Does the motor sound different when you pull the Start trigger? If it sounds a lot faster than normal, it could be an issue between the motor and gearbox.
Does the blade spin really easily and feel like it's not bolted down? Does the blade not turn at all like it's 'locked' or 'jammed'?
- A loose or floppy blade is commonly the centre mount bolt for the blade is loose or the blade isn't seated correctly.
- A 'locked' blade could be a gearbox or a motor issue.

Do Ray:
If the blade engagement lever is in the disengaged position, the belt will be loose, allowing you to turn the blades by hand. If you place the blade engagement lever in the engaged position (with the motor off) it will be hard to turn the blades because of the tension on the belt. If the blades are still easy to turn with the blade engagement lever in the engaged position, you need to replace the blade drive belt!

check to make sure the drive stud is spinning with the motor. If it is, make sure the blade assembly is lining up correctly as well as fitting tight on the drive stud. How to Repair Blender How to Repair Small Appliances Tips and Guidelines

Unfortunately, this is common on older model table saws. They do not have a blade brake and as far as I am aware it is nearly impossible to retrofit them.
If this is a newer model saw it's likely that the blade brake is malfunctioning and I have no experience with them.
Hope this helps and am very sorry if it doesn't.

Ken

Here some toubleshooting:

Problem 1. Fan will not start.
Probable Cause
1. Fuse or circuit breaker blown.
2. Loose power line connections to the fan, or loose wire connections in the switch housing.
3. Reversing switch in neutral position.

Suggested Remedy
1. Check main and branch circuit fuses or circuit breakers.
2. Check line wire connections to fan and switch wire connections in the switch housing.
3. Make sure reversing switch position is all the way to one side.

WARNING: Make sure main power is turned off.

Problem 2. Fan sounds noisy.
Probable Cause
1. Blades not attached to fan.
2. Loose screws in motor housing.
3. Screws securing fan blade flanges to motor hub are loose.
4. Switch housing binding against the blade hub.
5. Wire connectors inside switch housing rattling.
6. Screws holding blades to flanges are loose.

Suggested Remedy
1. Attach blades to fan before operating.
2. Check to make sure all screws in motor housing are snug (not over-tight).
3. Check to make sure the screws which attach the fan flanges to the motor hub are tight.
4. Check to make sure that the switch housing does not bind against the blade hub.
5. Check to make sure wire connectors in switch housing are not rattling against each other or against the interior wall of the witch housing.
6. Tighten screws securely.

WARNING: Make sure main power is turned off.

Problem 3. Fan wobbles
Probable Cause
1. Setscrew in motor coupling is loose.
2. Setscrew in the hanger ball/downrod assembly is loose.
3. Screws securing fan blade flanges to motor hub are loose.
4. Fan blade flanges not seated properly.
5. Hanger bracket and/or outlet box is not securely fastened.
6. Fan blades could be out of balance.

Suggested Remedy
1. Tighten the setscrew in the motor coupling.
2. Tighten the setscrew in the hanger ball/downrod assembly.
3. Check to be sure screws which attach the fan blade to motor hub are tight.
4. Check to be sure the fan blade flanges seat firmly and uniformly to the surface of the motor hub. If flanges are seated incorrectly, loosen the flange screws and retighten.
5. Tighten the hanger bracket screws to the outlet box, and/or secure outlet box.
6. Interchanging an adjacent (side-by-side) blade pair can redistribute the weight and result in smoother operation.

WARNING: FOR YOUR OWN SAFETY TURN OFF POWER AT FUSE BOX OR CIRCUIT BREAKER BEFORE TROUBLESHOOTING YOUR FAN!!!

Hope helps.

Hello. Most likely the nut which holds the blade tight has loosened enough that the motor spins the shaft but the blade just sits there and doesn't spin. This is an easy repair. You will need a large crescent wrench, or the properly sized open end wrench and a 2 foot long piece of 2x4 lumber. Use the lumber to "lock" the blade against the frame once you have the nut fairly tight. Then give it one more turn to be sure the nut doesn't loosen up on you again. It is best to do this job without turning the mower upside down as doing that will cause the oil to go into the air filter and then it will not start. If this is all basically greek to you ask a neighbor or a friend for help. It is really only a two minute job. J.

is the nut holding the blade assy tight? loose nut can cause this

It sounds like you got the cable to tight. The brake cable applys the brake to the pulley to help stop the blades when PTO is disengaged. With it being tight it might be applying the brake and that is the reason your blades are not running at full speed. If you keep using it that way it will wear out your brake and possibly damage a pulley. I suggest you loosen the brake cable or replace it with a new one.

If it's like mine (MM 875), it has a plastic "clutch" that has little edges on it that broke off when I was chopping sticks with the mower ;-) Went to the local B&D place and got a new one for less than $3.

But now I'm worrying about the nut holding the blade on -- if I try to get it good and tight, the plastic "clutch" spins around off-kilter... Funny how I never even looked at the blade after I bought the mower used, but never worried about the blade being loose and flying off.

check out toolpartsdirect.com for parts diagram.