Briggs & Stratton choke service 31P977

Instructional video on Briggs & Stratton choke service.

Craftsman Lawn Mower
Model: 917.276630
Ys4500 20hp
Briggs & Stratton Engine 31P977

After 4 years the engine had become harder to start and warm up. Eventually it ran rough even after presumably warm.

The problematic symptoms were:
1) Rough cold start
2) Decreased power
3) Rough idle
4) Black smoke from exhaust

I removed the engine cover and found the choke was sticking. It appeared that a choke return spring was missing until performing additional troubleshooting. I removed the intake manifold and the choke butterfly plate and found the plastic choke plate shaft was binding. I removed, sanded and cleaned it. Then I greased, resprung and reinstalled it. The choke no longer sticks and the engine runs like new.

Tools needed:
T40 Torx driver
10mm wrench
11mm deep well socket and ratchet
400 grit sandpaper
grease

Hope this helps!

Category:

Autos & Vehicles

Tags:

• Craftsman
• Ys4500
• Lawn
• Grass
• Garden
• Mower
• Tractor
• Briggs
• Stratton
• Engine
• 31P977
• Choke
• Sticking
• Stuck
• Rich
• Black
• Smoke
• Rough
• Idle
• Clean
• Fix
• Repair
• Service
• Cold
• Power
• Loss

[bullikins]

Thanks for posting this,it fixed me right up,for free !

[3ald3eaver]

@bullikins anytime!

[ccaine01]

Fantastic - exactly what I needed and saved me over $100 in service. Thank You

[3ald3eaver]

@ccaine01 Your Welcome. $100? That's if they fixed it the 1st time :-)

[3ald3eaver]

epic comment! Guess you're still learning how to pause YouTube and read annotations! Keep trying. You'll get it. Eventually......

[cubcadet2]

good video he just to talk us throught it and ZOOM in more but good chosse of the lawn tractor