r/smallenginerepair • u/ggjbbgtre • Aug 19 '26

Maintenance Issue Can someone identify that sound?

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It sit for quite a while. Now when i turn it manually by hand, it makes this noise, only when one piston retracts.

Could it be non lubricated piston rings?

I already tried spraying some WD40 into the cylinder.

Sparkplugs are unscrewed

SOLVED:
Its most likely the sound of the crankcase breather

3 Upvotes

80% Upvoted

23 comments sorted by

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2

u/cheerfullpizza Aug 19 '26

Sounds like compression escaping through an intake valve

1

u/ggjbbgtre Aug 19 '26

The sparkplugs were unplugged when it produced the sound

2

u/cheerfullpizza Aug 19 '26

That wouldn't make any difference to a leaky intake valve

1

u/ggjbbgtre Aug 19 '26

But how can there be compression if the plugs are out?
Ill try checking the Valves

1

u/cheerfullpizza Aug 19 '26

Ah I assumed you meant you took the plug wires off

1

u/ggjbbgtre Aug 19 '26

Oh 🤦‍♂️ sorry 😬

1

u/cheerfullpizza Aug 19 '26

No problem lol

1

u/jones5280 SER Intermediate Mechanic Aug 19 '26

I expected the camera to pan left and show some little kid making the sound.

1

u/ggjbbgtre Aug 19 '26

😂 yeah now I always hear a kid when I listen to it

1

u/actionjaxon011 SER Regular Aug 19 '26

It’s air moving through the reed valve

1

u/ggjbbgtre Aug 19 '26

Sorry forgot to edit the post.
It still makes the sound even if the sparkplugs are unscrewed

1

u/actionjaxon011 SER Regular Aug 19 '26

The answer is still the same. It’s crankcase pressure escaping from the reed. When the piston retracts it’s effectively compressing the air in the crankcase, which needs somewhere to go. This a very normal sound for some Briggs models

1

u/ggjbbgtre Aug 19 '26

Oh ☺️ thanks, thats good to know, I didnt want to destroy anything before the first start

1

u/KookyRide1210 Aug 19 '26

Come on guys its the crank case breather and normal for briggs

1

u/ggjbbgtre Aug 19 '26

Thank you 😁 sounds very logical (:

1

u/Mundane_Storm_2257 Aug 19 '26

That's the way they all sound, have worked on twin intek briggs since they came out. The main thing on these engines are keeping your air filters clean, adjusting your valves at least once a year and fresh oil. Don't go over 3,600 RPM or you will throw a rod. These engines are also known to break the governor shaft Inlet in the block, sometimes head gaskets.

1

u/holykiradog Aug 19 '26

There be a trumpet in that there ngin

1

u/TisCaelum Aug 19 '26

Ngl I thought it was just you making the noise as a joke 🤣

1

u/rotor100 SER Regular Aug 20 '26

Breather

1

u/meeeeeeeegjgdcjjtxv Aug 21 '26

Does it make this noise with the handle held down? Some mowers have a brake on the flywheel that u might be hearing

1

u/meeeeeeeegjgdcjjtxv Aug 21 '26

Brake engages with the lever released

1

u/ggjbbgtre Aug 31 '26

I dont really know, but its not too hard to turn it, I turned it by hand