B&S 21 HP Platinum backfiring

[ckilbu02]

Hi everyone,

I have spent many hours researching my issue and well... I am apparently just not mechanically inclined (but am looking to improve and save some money!).

Yesterday, while I was mowing, my Craftsman YT 3000 began to sputter and backfire. The motor continues to run and I have no problem starting.

I allowed for it to sit 24 hours, however the issue is still there.

When idling at higher speeds, the backfiring seems rhythmic under both high and low RPM.

Gas seems to be getting to the carb okay, the spark plug seems good (maybe a little soot), and I am lost from here.

Attached is a video detailing the sound at higher RPM and then lower.

Any help is very much appreciated.

 

[Tinkerer200]

Water in your gas could be a cause, check carb. sediment/float bowl. Check valve clearance. I have detailed instructions on valve adjustment IF you like, address below, put in proper format and remind me, engine model number and what you want.

Walt Conner
wconner5 at frontier dot com

 

[ckilbu02]

Water in your gas could be a cause, check carb. sediment/float bowl. Check valve clearance. I have detailed instructions on valve adjustment IF you like, address below, put in proper format and remind me, engine model number and what you want.

Walt Conner
wconner5 at frontier dot com

Thanks for you reply. I got some advice that it is likely an issue with the float in the carb allowing too much fuel flow. I also have some fuel in oil, I've found.

I am going to try and overhaul the carb and see if that fixes the problem. And of course, change the oil.