Small engine throttle: When did this happen?

[Oggie]

""Bah! You kids get outta my yard!"

"Turn that noise down!"

Now, I can add a new geezer rant: "There's not really a throttle on my push lawnmower!"

I remember, way back, the "throttle" on a lawnmower actually controlled the gas/air mix going into the carburetor.

Well, the engine on our 8 or so year old lawnmower died and I had to replace it.

What I thought was the throttle linkage on the new engine had to be modified to fit the old controls and, as, I was fiddling with it, I realized that what both the old engine and the new engine had was not a traditional throttle, but more a speed control that adjusted the engine's governor.

After some Internet research, I think that the top speed of the engine is set where the tip of the lawnmower blade will travel less than 19,000 feet per minute.

Anything I do with what I was thinking was the throttle just adjusts the governor to slow the engine down. The carburetor is always set to run at the specified engine speed.

So, if I want the blade to spin faster to get that he-man power tool buzz, it's going to be more complicated than I'm willing to figure out.

Killjoys.

[HermitJohn]

For some time now, most push mowers are locked to one governor setting. what people thought was throttle cable back in the day just set the governor to try to maintain a certain rpm. It didnt ever adjust the throttle plate itself, the governor has always adjusted the throttle plate to maintain a certain rpm under varying load conditions. You just used to be able to change that governor setting using what you thought was a throttle cable. The engine governor will do its best to keep that speed. They lock it to one speed nowdays because an engine running at high constant rpm pollutes less than one at varying speeds. High rpm also means you dont need a choke. You punch the plastic pimple until enough gas gets to carb to start engine then it goes into high speed mode and can get by with no choking. If you notice, lot push mowers have no choke just the plastic pimple.

[jwal10]

I have a speed control on my mower. It is 56 yrs old. ME.... and the spring must be getting weak. It is an old push reel mower, cast iron wheels and a wood handle but light enough I can shoulder it all over town, cuts 16" each pass. I even have 2 spares for parts hanging in the garden shed. Grandpa bought it in 1937 from Monkey Wards and Co. I hone the blades every year, it mows 16 yards once a week whether they need it or not, March through October, some yrs into Nov....James

[JohnL751]

Originally Posted by jwal10

I have a speed control on my mower. It is 56 yrs old. ME.... and the spring must be getting weak. It is an old push reel mower, cast iron wheels and a wood handle but light enough I can shoulder it all over town, cuts 16" each pass. I even have 2 spares for parts hanging in the garden shed. Grandpa bought it in 1937 from Monkey Wards and Co. I hone the blades every year, it mows 16 yards once a week whether they need it or not, March through October, some yrs into Nov....James

I have one of those old mowers, I just need a good woman that will use it!

[foxtrapper]

Originally Posted by Oggie

What I thought was the throttle linkage on the new engine had to be modified to fit the old controls and, as, I was fiddling with it, I realized that what both the old engine and the new engine had was not a traditional throttle, but more a speed control that adjusted the engine's governor.

That's not new fangled, that's as old as governors. Go look at the century + old hit and miss engines, you'll see the same thing there.