How a Mechanical Governor Works on a 4-Stroke Lawnmower Engine

This How a Mechanical Governor Works on a Small Four Stoke Lawn mower Engine.

This video shows you how the mechanical governor works on a 4 Stroke Lawn mower, but the principles of this can be applied to the workings of an Engine Governor in general.

So, whether you are using a Riding lawn mower, Push mower, Petrol lawnmower or even an electric lawn mower, this principle could possibly be valid. The Robot Lawn mower doesn't escape this principle either!

Four-stroke internal combustion engines frequently employ a mechanical governor system to control engine speed and maintain a constant RPM (revolutions per minute) under a variety of load circumstances. To maintain smooth operation and avoid overspeeding or underspeeding, the governor system helps regulate the fuel flow to the engine.

A four-stroke engine's mechanical governor system is described in the following manner:

The mechanical governor system consists of the following essential components:

Flyweights, a control lever, and the governor shaft are all part of the governor assembly.
The throttle regulates how much gasoline and air are injected into the engine.
Control Springs: The governor system requires a certain amount of tension from these springs in order to function properly.
The governor assembly is joined to the throttle mechanism by linkages.

Sensing Engine Speed: The governor system keeps track of the engine speed. This is accomplished either by a governor gear installed on the flywheel or by a magnetic pickup that measures the engine's rotational speed. The governor assembly is connected to the governor gear, also known as the magnetic pickup. Two flyweights are a part of the governor assembly and are fastened to the governor shaft. The flyweights are subjected to an increase in centrifugal force as engine speed rises. The governor shaft is rotated by this force, which also causes the flyweights to travel outward.

Control Lever and Linkages: A control lever that is attached to the throttle mechanism is connected to the governor shaft. The control lever is engaged when the flyweights shift outward as a result of increasing engine speed, and it changes the throttle position appropriately. The control lever limits the throttle if the engine speed is too high, decreasing the fuel supply to the engine. The control lever closes the throttle to decrease the fuel flow when the engine speed rises.

The governor system works on the basis of a feedback mechanism. The engine speed is impacted as the throttle position is changed by the control lever. The governor gear or magnetic pickup detects a change in engine speed, and the flyweights adjust to maintain the correct RPM.

The governor mechanism also makes adjustments for changes in load. The governor system detects the decrease in engine speed when the engine sees an increase in load, such as when more devices are connected or the workload increases. In response, it opens the throttle to give the engine more fuel, making up for the extra load and keeping the appropriate RPM.

Overall, a four-stroke engine's mechanical governor system is crucial for controlling engine speed and guaranteeing reliability. The governor system keeps the RPM steady so that the engine can run smoothly and efficiently under a variety of load conditions by monitoring engine speed, spotting variations, and regulating the throttle position.

I hope you gain something from this.

Many thanks indeed

Craig (Owner and Creator of The Repair Specialist Channel)

#MechanicalGovernor
#EngineSpeedControl
#FourStrokeEngine
#RPMRegulation
#EnginePerformance
#ThrottleControl
#Flyweights
#LoadAdjustment
#ConstantRPM
#GovernorSystem
#EngineGovernor
#EngineSpeedSensor
#FlywheelGovernor
#MechanicalControl
#ThrottlePosition
#LoadVariations
#EngineStability
#GovernorMechanism
#ControlLevers
#SpeedFeedback

[nomusicrc]

Great video no loud introduction straight to the point and no music while you were talking

[barrybebenek]

That sir is one of the BEST descriptions of that system I’ve ever seen. 👍🏼🇨🇦

[flhtcui]

Great video explaining how an internal governor works. Extra bonus points awarded for having an actual engine cutaway to illustrate. Well done Sir. Well done indeed.

[jumboegg]

Yes it is ingenious. When the mower engine bogs down in some heavy grass, the governor opens up the throttle and gives it more fuel to try and keep the RPMs up.

[Mylifelovingit]

Well explained. Short and to the point. No waffling, no interference from background music. Well done!

[Bigeye]

What can I say, absolutely brilliant demonstration, was always wondering how the governor works, thanks very much greg

[Billy_Bad_Ass]

Wow, I finally understand how these accursed governors work for small 4-S engines! Especially the linkages always had me baffled.

[tehe]

I couldn’t find a video that explains it as clearly as this, thank you so much!

[gregoryfalat]

You unlocked a lifelong mystery for me. Thanks

[discobiscuit]

Been trying to find out how these work for years. Thanks for taking the time to explain this.

[bryonhampshire]

Perfect explanation on how the governor system is supposed to work. Thank you!

[drvanon]

Congratulations on making an absolutely brilliant video. Extremely clearly explained, without much a do about nothing. Few videos are this straight to the point and clear.

[leh]

Right on 'dynamic' demo. There is nothing quite like a dynamic demonstration, and your's is Well Done.
Thank you!

[Brian_L_]

You are the engine doctor, i never figured out how my generator was able to keep constant RPM, you solved my mystery. Amazing presentation & well done Sir 💯

[appatula]

This is absolutley brilliant. Not to say your previous 2d graphical animations weren't fantastic but this is top notch when it comes to the educating people in regards to the internal and mechanical aspects of machinery and mechanisms, it just cannot be beat. It's a shame that teaching like this has become a "thing of the past". Mentors like you are not as plentiful as they used to be and are certainly not like were in the 60's!

[MrFiction]

Yesterday I didn't even know what a governor was, I just knew "something" was acting up on my snowblower. This video and another one on another channel taught me how the ideling(?) in the carburator worked and what part the governor plays in the whole of it. Thank you from Sweden! 🇸🇪

[codyramos]

If your lawn mower has a hunting rpm ( revs up and down almost shutting off in a never ending cycle) or when it starts it revs up high to fall on its face and turns off not wanting to stay running .. the carburetor is dirty ..
some carbs have a center bolt under fuel bowl on the carb this is your primary jet
remove the bolt ( if the bowl stays on that's fine one thing at a time ) with the proper size socket or wrench .. make sure it's passageway that runs through the center and the little hole that's undee the bolt head is clear . Put the bolt back on the carburetor and it should be good to go. ... showed my buddy this some years back ... he would picked up ever mower thrown out on the curb clean the carburetor and sell it to pawn shop... guy was making almost $400 a month doing this at one point.

[benjaminmellingen]

Amazing video! This is the first time I feel like I UNDERSTAND how the governor works 🎉

[rickydale]

The best explanation i’ve seen in years. Ricky Huntsville, Ala.

[mmsm]

That was an excellent explanation of how the governor works.