RPMs of small engines

Tom RS

Member
What is the typical low and high rpm of most small engines? For example a 8 HP Tecumse snow blower engine.
 
High RPM for most of them is 3600, low can run around 1500.
If you idle them too low, they don't blow enough air or splash
enough oil for a long life.
 
Steve is pretty much correct. Sometimes the OEM specifies a different rpm.

For example, Briggs and Stratton generators specify no load at 3750. (So at full load it will be turning about 3600.) They call the speed loss 'governor droop'.

Some Briggs Vanguard engines on 'swamp boat' motors turn 4200. Pretty much that same engine in a lawn and garden application is rated at 3600.

On certain zero turn mowers that needed a little more 'oomph', the rep let us set fast idle to 3700.

A lot of push mower engines are set around 3200 to 3400 rpm. I think due to a limit in blade tip speed. This may be a government requirement, maybe. (as if a blade moving at 3200 rpm won't do as much damage as a blade at 3600 rpm.)

Some of the smaller 1 cylinder Honda engines get a lean surge above 3400 rpm. So I guess that is about their max where they are designed run well.
 
All of the answers are very close. Generators run at 3600 so you get your 60 cycles. Take 3600 and divide by 60 gives you 60 cycles. And as stated you need enough of an idle to have lubrication. That is about all I can think of.
 
I had an old Snapper walk-behind mower with a leaf grinder attachment and a bagger.
The bagger didn't pack very well until I adjusted the governor up to 4200 rpm.
The engine ran ok that way for about one season.
 
I always had the impression you might work on small engines or have a small engine shop,would you be interested in bunch new parts etc from a closing out lawm mower shop
 

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