How to replace timing belt and how to pullout the bearing.i open but the bearing I can't pullout

The same answer as I replied yesterday. You use a flywheel extractor kit or a 3 legged puller. The flywheel is on a Morse taper with a half moon keyway.

https://www.google.com/search?q=Ryobi+RY251PH+trimmer%2C+how+to+remove+flywheel

..And the same videos as yesterday plus one. All the engines are the same as far as flywheels go.

There are a few potential remedies for a humming motor on a Proform 395e elliptical:

1. Tighten any loose parts: If the humming noise is coming from the motor, it could be caused by loose parts that are vibrating against each other. Try tightening any screws or bolts that may be causing the noise.
2. Check the belt: The belt that connects the motor to the elliptical's flywheel may be loose or damaged, which can cause a humming noise. Tighten the belt or replace it if it is damaged.
3. Check the flywheel: If the flywheel is damaged or out of balance, it can cause the motor to vibrate and make a humming noise. Check the flywheel for damage and replace it if necessary.
4. Check the motor bearings: If the motor bearings are worn or damaged, they can cause the motor to vibrate and make a humming noise. Check the motor bearings and replace them if necessary.

If you are unable to identify the source of the humming noise or fix it yourself, it is recommended that you contact Proform customer service or a qualified technician for assistance.

I don't know the official air gap but it needs to be as close as possible without touching the flywheel - bear in mind the flywheel will expand as it gets hot. I find 8 thou (0.008") works well with small engines.

The louder noise and burnt smell possibly was the bearing getting worse, or going out, causing the belt to slip over the pullet and start heating up.
Was it a burnt rubber smell?

I don't see how this could have anything to do with the flywheel though.

follow this steps and fix it. God bless you
Use a flat screwdriver to unseat the tabs that hold the front top cover in place. This will expose the flywheel and pedal arm connection points. Rotate the flywheel by hand and determine whether lubrication will accomplish the repairs. If the bearings are exposed, use a grease gun with an extension nozzle and lubricate both bearings with lithium grease. If the bearings are damaged or sealed, proceed to the next step.

2

Remove the front and side covers on the main frame. Hold the flywheel with one hand and use a box wrench to loosen the bolts that secure the pedal arms at each side of the flywheel. Pull the arms away from the flywheel and remove the bearings from each side.

3

Test the bearings as before. Lubricate exposed bearings with lithium grease and reinstall them. Sealed bearings must be replaced. Reattach the pedal arms to the flywheel. Replace the main frame covers and front top cover to complete the repairs.
Lubrication

1

Detach the ends of the pedals from the crank axles. Spread a layer of machine grease over the crank axles, then reattach the ends of the pedals.

2

Remove the bolts connecting the pedals to the swing arms. Detach the pedals from the arms, then spread a layer of machine grease over the axles on the swing arms. On some models, the bolts may also serve as the axles. Reattach the pedals to the arms.

3

Remove the bolts connecting the swing arms to the elliptical's upright. Detach the swing arms from the upright, then spread a layer of machine grease over the axles on the upright. Reattach the arms to the upright.
Drive Belt

1

Remove the screws or bolts securing the ends of the pedals to the crank axles. Slide the ends of the pedals off the axles. Remove any screws or bolts securing the left and right disc shields to the base unit. Pull or pry the disc shields off the base unit and set them aside.

2

Remove any screws or bolts securing the left and right side shields to the base unit. Detach the side shields and set them aside. Examine the interior of the base unit and locate the drive belt.

3

Pull the drive belt free of the crank pulley, flywheel and any other pulleys. Discard the old drive belt and install a new belt in its place. Turn the crank axles by hand to confirm that the belt will turn smoothly when the device is in use.

9 out of 10 times the issue is a worn out clutch bearing or "one way needle bearing". Freemotion and Nordic Track are both owned by ICON Fitness. This technology for fitness equipment comes from the original Nordic Track skier. In the skier, there is a flywheel with an axle through it in the middle with skis left and right. Under each ski just about center of the length is a rubber roller that fits over the flywheel axle. Inside this roller is a "one way needle bearing". That is, when you push to the rear with the ski, the bearings rollers will shift and lock against the axle and engage the flywheel. When you pull the ski back forward the rollers inside the bearing release the axle and allow free movent forward untill you again push to the rear. Many poor souls were sold new skis and tension straps in most cases to no avail. What needed to be replaced or rebuilt were the rubber rollers under the center of each ski with the "one way needle bearing clutch" inside. The same technology is used inside this exercise bike except that the "one way needle bearing" is pressed directly into the flywheel itself. So rather that replacing or rebuilding the "roller clutches", you need to replace or rebuild the "flywheel". The price for the flywheel from ICON is $600 plus. Thats right $100 more than you probably paid for the bike. There used to be businesses that rebuilt the roller clutches for the skiers. There is no rebuild service available for the flywheel on this bike. So if you don't buy the maintenance contract witch will cost you as much as the bike for 4 or 5 years you have a very heavy piece of junk to dispose of. This is planned obsolescence at it's best. If you are very handy. You can disassemble the bike and find a commercial machine shop that can replace the bearing for you. It is sandwiched between roller bearings on each end. You will need a press designed to remove and replace bearings for commercial machinery like conveyor belts and assembly line equipment and someone to order and replace the same or an equivalent bearing. This actually should be a relatively affordable service. At least in comparison the only other option.

Step 1:

please follow the instruction and fix it. God bless you.
Pedal Arms

1

Use a flat screwdriver to unseat the tabs that hold the front top cover in place. This will expose the flywheel and pedal arm connection points. Rotate the flywheel by hand and determine whether lubrication will accomplish the repairs. If the bearings are exposed, use a grease gun with an extension nozzle and lubricate both bearings with lithium grease. If the bearings are damaged or sealed, proceed to the next step.

2

Remove the front and side covers on the main frame. Hold the flywheel with one hand and use a box wrench to loosen the bolts that secure the pedal arms at each side of the flywheel. Pull the arms away from the flywheel and remove the bearings from each side.

3

Test the bearings as before. Lubricate exposed bearings with lithium grease and reinstall them. Sealed bearings must be replaced. Reattach the pedal arms to the flywheel. Replace the main frame covers and front top cover to complete the repairs.

Step 2:

LUBRICATION

1

Prepare to oil by filling a grease gun with lithium grease. Check your owner's manual for the exact type of grease for your unit.

2

Locate where it is you need to lubricate. Focus on the bearings, free-moving joints and attachments with moving parts such as handle bars, wheels, pedals arms and guide rails. Go to each location one by one when greasing.

3

Unfasten the bolts or screws that hold the joint or attachment that you wish to lubricate.

4

Grease each bolt and screw liberally. Tighten each bolt and screw back into its place when finished.

5

Wipe away any excess greas

Step 3:

Drive Belt

1

Remove the screws or bolts securing the ends of the pedals to the crank axles. Slide the ends of the pedals off the axles. Remove any screws or bolts securing the left and right disc shields to the base unit. Pull or pry the disc shields off the base unit and set them aside.

2

Remove any screws or bolts securing the left and right side shields to the base unit. Detach the side shields and set them aside. Examine the interior of the base unit and locate the drive belt.

3

Pull the drive belt free of the crank pulley, flywheel and any other pulleys. Discard the old drive belt and install a new belt in its place. Turn the crank axles by hand to confirm that the belt will turn smoothly when the device is in use

the ryobi s430 has a hole in the timing wheel with ,perhaps a red mark on it or next to it like mine.lining that up with the piece at the bottom that goes straight down puts the cam lobes right at 180 degrees away from the rockers and readies the valvetrain for the compression stroke.if you remove the valve cover,which by the way has a really tough reusable gasket,youll see the cam and rocker arms.you want the lobes of the cams to be as fara away from operating the rocker arms as possible.next, you ll find top dead center to be not quite lined up, with respect to magneto edges and flywheel magnets.using a tiny screwdriver, you can put the tip in the spark plug hole not quite an inch and rotate the flywheel SLOWLY.being careful not to somehow allow the screwdriver to become pinched between the piston and cylinder(that spark plug hole is at a funky angle)at some point,youll fee fell the piston approach top dead center.youll notice there are a few degrees that the flywheel will turn before the screwdriver will fall back down,indicating travel has begun toward bdc(bottomdead center).you want the crank asembly to be set in the center point between when the screwdriver stops rising out of the spark plug hole to the point it just starts to fall back in.that should be close enough.my problem now is getting the timing belt OFF.mine is bad and I've torn down all the way past the flywheel.at this point,i can see the timing belt,but now there's this pressed bearing in the way that ive yet to figure out how to remove.viva la ryobi

The flywheel belt would have broken or gone slack and fallen off the motor pulley. You can confirm this by opening the top and looking inside. If you can shake the machine holding it upside down the belt might even fall off.Replacing the belt is a tricky job. Its like putting back a bicycle chain except there is a metal plate behind the flywheel and your hand won't go there.