You are here:

Small Engines (Lawn Mowers, etc.)/opver reving, no throttle control


QUESTION: I am about to work on a mower for my landlord. It is a MTD Tradesman with a Briggs & Stratton 18 hp opposed twin model #422707 1214-01. He has played with adjustments just to cheap(keep) it running and is now flooding to the point of gas visibly puddled in the intake pipe seen thru the carb. I believe he has adjusted the governor if it is the screw on the linkage on the front of the motor just behind the carb. Do you have any precautions about this adjustment or anything else to know about the high rev I should know before I just tear into it?????? The throttle linkage seems to be intact although VERY loose and barely moves the butterfly in the carb at full throttle position. Please help. Tom

ANSWER: Perform a "Static" governor adjustment BEFORE doing anything else.

Procedure link:

Once you know the mechanical governor static adjustment is correct then you can tackle the fuel issue. Probably a dirty carburetor or leaking inlet needle seat is causing the flooding issue.

If you think the linkage(s) are not correct you can use Google images and find all sorts of pictures on the linkage set-up.


---------- FOLLOW-UP ----------

QUESTION: thank you very much. i went to the governor setting link you suggested and it is very discript but it is not for the 422707 1214-01 model. is this procedure somewhat non model specific?

Did you read the mechanical governor section?  Static governor adjustment is the same for all engines.

Specifically, steps 2 and 3.

2.Move the throttle plate linkage until the throttle plate is wide open (image D)
Image D. (To find the wide-open position, first position the throttle lever against the idle speed screw or a fixed stop plate. The throttle is wide open when it is all the way in the opposite direction.) Note the governor arm's direction of rotation as you move the throttle plate to the wide-open position. This is important for the next step.

3.With the throttle plate wide open, use a nut driver or wrench to turn the governor shaft in the same direction that the governor arm traveled (image E)
Image E.

Briggs engines are a little more forgiving if the governor is not properly adjusted as the internal governor arm will usually not break if the governor is not adjusted.  You will know immediately if the governor is not adjusted properly as the engine will rev way too high when started.  Shut it off ASAP and re-adjust governor.


Small Engines (Lawn Mowers, etc.)

All Answers

Answers by Expert:

Ask Experts


Eric A. Jones


Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.


Born and raised in the midwest. Started tinkering with engines when I was about 14 on my Suzuki RM-80. I began lawn mower repair at a small hardware store. I knew absolutely nothing. I read lots of repair manuals and met an older fellow who taught me many lessons. I continued working on small engines through high school and paid my way through college working on mowers at the same hardware store. Decided to get away from the midwest and mower repair so I joined the Air Force. I repaired air traffic control electronic equipment and ended up in Hawaii where I got a part time job at Small Engine Clinic. I gained a lot of experience from the Small Engine Clinic and had a blast repairing small engines. I then took the Briggs and Stratton Master Service Technician test and earned my MST. I then traveled to Wisconsin where I attended the factory update training seminar and received formal training. Continued working on mowers part time as I completed 20 years of military. Retired from the military on a Friday and continued in the lawn and garden industry the next Monday.

MAS Aerospace Operations BA Mathematics AAS Electronic Communications AAS Electronic Technology

©2017 All rights reserved.