Is your riding mower engine surging mostly UNDER LOAD at MID RANGE THROTTLE / RPM? Check this somewhat hidden and fragile carburetor linkage spring first before digging deeper (ie. check the easy stuff first before tearing things apart). You may get off lucky & easy as I and many others have.

Video Chapter Index:
0:00 Intro & Surging Demo
0:27 Problem Explanation
1:10 Other Items I First Checked Didn't Fix The Issue
4:29 THE ACTUAL PROBLEM
5:50 Water Cooler

If your carburetor linkage antislack / governor spring is intact after checking it, then cross that item off the list and start looking deeper into the diagnostic trouble shooting surging process. Another common issue with these carburetors is a dirty main jet or pilot jet, but those usually show up under higher or full throttle.

The broken or stretched governor linkage spring on the other hand almost always shows up under partial throttle and while coming off idle as the carburetor butterfly is literally "fluttering". At full throttle it usually goes away because the butterfly valve stops fluttering due to the increase in airflow & engine speed; or at least becomes less noticeable.

This easy riding mower surging fix was made to a John Deere D/100 series, but will apply to many other brands of residential lawn tractors that use the same / similar type Briggs & Stratton Intek engine/carburetor.

May 2024 Update: @350 HRS on the clock. That original antislack spring I fixed 6 years ago now is still working fine and hasn't broke at the new bend location as some suggested it immediately would take that for what it's worth anecdotal. I did order a new spring (see part # below), but no point fitting it until this one breaks again (if it ever does).

Link to Briggs & Stratton governor link spring part # 691842:
https://amzn.to/33FP9ld

If you enjoyed this riding mower video, here are some others you may be interested in.

1. DIY riding mower yearly maintenance:
   • How To Maintain A Riding Mower  Easy...  

2. Riding mower deck removal & maintenance:
   • Riding Mower Deck Maintenance  Keep ...  

3. Riding mower mulching blades do they work:
   • Riding Mower Mulching Blades Review ...  

4. Riding mower LED Headlamp conversion:
   • Riding Mower LED Headlamp Conversion ...  

5. Riding mower squeaky rear wheel fix:
   • Squeaky Wheel Gets The Grease  

Please consider giving a thumbs up & subscribe if you enjoy my content thank you & thanks for watching :)