Riding Mower Engine Surging - Easy & Inexpensive Fix!

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 anti-slack / 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 anti-slack 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:

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[Rchelicopterfun]

June 2024 six year update with 350 hrs now. This spring repair is still holding.

[clintstevenson]

That is EXACTLY what that spring is for. Tightens up linkage slop to help prevent surging. Thanks for the video

[AbalengHero]

My husband has been teaching me how to fix things.. Hes at work today and I was to mow.. Unfortunately I havent been taught about the Snapper we have, but thanks to this video I was able to see our "slop spring" has been disconnected and could be my problem today. Lord willing that fixes it, and my husband will return from work and see his wife didnt need him to show her how this time 😍

[morriswaller]

Must have spent 4-5 hours off and on trying to figure out why my Kohler 19hp started surging. Your video was the only one I found that talked about the governor spring. I re-connected it and problem solved. Your videos are very high quality, clear and concise. Thank You! Your time and effort in producing these videos are much appreciated!

[zarb]

Im really not sure what this spring is for, i really dont know. How wonderfully refreshing. A man who doesnt have to pretend he knows everything but knows enough to get the job done.

[RickyPisano]

I'll be darned!! I have a Kohler Courage 19 HP and this is EXACTLY what was wrong. I reattached it and it's running beautifully now. Incredible!! Talk about a quick fix!!! Awesome!! THANKS!!!!

[edmckinney]

My D105 John Deere developed this issue after 1 year of ownership. Small Engine repair claimed it needed a new carb that cost $350.00 bucks. I wouldn't pay so I lived with the misfire and surging for a couple of grass cutting seasons. I finally ordered a carb through Amazon for $25.00 dollars and 6 weeks later from China I put it on. Still had the same issue so I checked the Governor linkage and adjusted. Run's great now. I retired recently from my 45 year career repairing Industrial Machinery and Electronics. Now I have time to repair my own stuff. Not get ripped off by unscrupulous small engine shops.

[outfoxedgameingfgg]

You literally have no idea how much you helped me, we spent a hours upon hours and it was literally so easy. Thanks again keep it up.

[mattnichols]

I was so mad with my lawnmower i almost pushed it by the road and got rid of it. You video saved me thankyou!!

[boblowrey]

THIS IS ABSOLUTELY THE FIX! THE GOVERNOR SPRING IS ESSENTIAL! I DIDN'T BELIEVE IT UNTIL IT FIXED MINE! NOW SHE'S SMOOTH AS GLASS!!! THANK YOU MR. SALT!!!

[hans-jurgenwiegand]

I was so tired from working in the garage, that I fell asleep watching it the first time! You definitely caught my interest, so when I woke up, I watched it again, was very impressed, & subscribed & liked your video! I’ve always been better @ breaking things, than fixing things, from lack of knowledge & a good teacher. I think this is a great video, thanks!👍🏻

[airforcegamer]

i almost ripped the carburetor off, decided to look up the symptoms and found this video...thanks, saved me a lot of unnecessary work...my spring wasn't broke though it was just gummed up and stuck...i played around with it and now the surging has stopped :)

[jm]

Great close ups, and good explanation of the issues, sometimes it is the simplest fix's that are overlooked. This was a great tutorial, Thank you.

[handsomeyousy]

Incredibly rescue!! I have a Honda HRR 216vka, was doing fine until the other day I pushed it deep into bushes then it started surging high and low. I already called warranty but saw your video last night so I checked it today, exactly same issue due to a spring not attaching anywhere. Took me 2 seconds to figure out where to attach it back. Thank you much for your video!!

[winfordnettles]

My 1980 Craftsman GT18 began having the same problem as described in the video a couple of weeks ago. I tried all the common fixes, flushing and cleaning the fuel system, replaced the filter, fresh fuel, checked the spark plugs, checked the air filter, etc. Now, after watching this video, I realize that I might have missed this dampening spring. I hope this works, as I love my GT18. Thanks again for posting.

[hawkenman.]

You just taught me a $100.00 dollar lesson. Thank you my brother.

[mikejohnson]

HOLY SHEET! I can't get over how clean the lawnmower is. I mean that is better than new from the factory. Weird.

[gregfair]

John, dude! THANKS! - I had the same exact problem on a John Deere LA115, saw your video and just stretched the spring a little and... Vwa-Lah, the engine stutter went away, like magic! Thanks a million!

[shack]

Even after watching your video AND Looking at my machine, I couldn't, for the life of me, figure out WHAT does that spring even do?
But I tell Ya, JOHN, You nailed it!! Sure nuff, I did exactly what you did and the revving stopped.
THANK YOU --- THANK YOU --- THANK YOU

[am]

Thank you Mr. Salt for your video and thanks to Exinanition
for your
excellent explanation; my Kawasaki went into the permanent idle mode while mowing at full throttle ( I am a one-man, self employed landscaper), after a visual inspection, I saw the broken end of the spring hanging down and after pulling on the spring, engine revved up. Found some plyers, bent the spring and attached it to a screw hole; finished the mowing job and loaded the mower. Thank again guys! (and
AbalengHero, God bless you; your husband is a lucky man!)