How to fix this sound - Briggs 500e series engine lawn mower

[kikoman7]

First, this lawn mower did not start at all. I replaced the spark plug, cleaned the carburetor, changed oil and gasoline, cleaned the flywheel (there was grass stuck to it, removed it a bit with a screwdriver) and the engine worked (hooray!).
BUT: the engine now makes a rattling noise. It is very loud and disturbing. The mower also vibrates a lot. I made a video of it:

https://drive.google.com/file/d/1sDZDR9F7DOrkUSiaalYoaWU1misXTKza/view?usp=sharing

The lawn mower is a Briggs&Stratton 500e series, model no. 09P602-0002-H1.

I hope someone can help me
PS: sorry for my English, I am from Belgium (Europe)

 

[Tiger Small Engine]

First, this lawn mower did not start at all. I replaced the spark plug, cleaned the carburetor, changed oil and gasoline, cleaned the flywheel (there was grass stuck to it, removed it a bit with a screwdriver) and the engine worked (hooray!).
BUT: the engine now makes a rattling noise. It is very loud and disturbing. The mower also vibrates a lot. I made a video of it:

https://drive.google.com/file/d/1sDZDR9F7DOrkUSiaalYoaWU1misXTKza/view?usp=sharing

The lawn mower is a Briggs&Stratton 500e series, model no. 09P602-0002-H1.

I hope someone can help me
PS: sorry for my English, I am from Belgium (Europe)

It is most likely either the cheap recoil mechanism hanging up and dragging, or really bad connecting rod knock indicating engine wear and slop. Hard to say without being there in person.

 

[kikoman7]

Thanks man!
It could be the cheap recoil mechanism, but it doesn't look like that's the problem. Maybe I can put some WD-40 on some points there (on the white plastic bits under the hood) to see what happens? I'm definitely going to check on rod knock, but I'm still waiting for the delivery of my brand new socket wrench set to access the inside of the engine.
Just wondering: I can move the flywheel/fan back and forth and up and down a bit; is this normal? Here's a video of it:

https://drive.google.com/file/d/1t6cQz3CY6gxFN3_opFIGc0VhWrfLAl1X/view?usp=sharing

Thanks for helping me!

 

[slomo]

Sounds like she is out of oil. Put her on the full mark and nothing less. Underside of deck clean? Definitely sounds mechanical and struggling. Fishing line wrapped around the blade? Something is up. She is struggling for rpm.

 

[oldntired55]

i have a 20HP briggs on a craftsman rider, makes a similar noise. disassembly showed too much clearance on the counterweight rods. anyone else experience this? runs great , mows well...just that annoying rattle

 

[kjonxx]

Crank is bent and blade is hitting thus the vibration and constant banging. Look uner deck for shiney spot to confirm.

 

[Auto Doc's]

Sounds like low oil and a bent blade from hitting something hard.

Disconnect the spark plug wire tilt the mower so you can see the blade on the underside. Slowly turn the blade and watch for unevenness as you turn it. Blade may also be loose.

 

[kjonxx]

I agree and I should have said to remove the plug then tip on its side and rotate the blade

 

[kikoman7]

Thank you all for your response!
I have been able to check out a fair amount in the meantime. The blade is definitely not bent, there are no shiney spots of the blade on the metal cap either. The flywheel is cleaned (bottom + top; there was a lot of grass in between).
The flywheel key is still perfectly fine (no scratches). I changed the oil with SAE30 (as specified by manufacturer).
When I wanted to take the old oil out, (very) little came out. When I put the SAE30 oil out, it came back out pitch black.
Finally, I took off the cap of the self puller (I think, am not sure). Here was a metal bar loose in the plastic cap (check pictures):

20250429_181940.jpg

drive.google.com

20250429_181945.jpg

drive.google.com

I fixed this metal bar back into its place, but when I put the motor back together, the noise was still there. I am now thinking that a bearing is broken. It is (I think) anything inside the motor. What do you guys think?

 

[Auto Doc's]

This is appearing to need and engine. Small engine warehouse is a good source, but they are not cheap. You may be better off shopping around for another mower, or a good used engine on Ebay.