Idle and high throttle rpm?

[T4R11]

Any suggestions on what the idle rpm and high rpm should be on a 24hp/3600rpm engine?

[SawyerTed]

Not knowing the brand of engine and relying on my memory, low idle should be 1100-1200 rpm. Wide open throttle with no load 3,600 to 3750 rpm. 

[T4R11]

Thanks. It is an Onan

[Chuck White]

If I'm thinking correctly, the book for the ONAN that was original on the LT40HD that I had, stated that a LOW RPM of 1800 and HI RPM of 3600 is the standard setting!

[T4R11]

Chuck, thanks! I tried every combination of governor spring, throttle solenoid adjustments etc. and the optimal numbers I got were the numbers you referenced. 

[sawguy21]

Chuck is correct. Stationary air cooled engine carburetors don't have a power valve or accelerator pump and will stall when the throttle is suddenly opened if the idle is set too low.

[Ben Cut-wright]

Chuck is correct. Stationary air cooled engine carburetors don't have a power valve or accelerator pump and will stall when the throttle is suddenly opened if the idle is set too low. Idle speed isn't a factor as the engine is running at rated max when the clutch is engaged.

I've seen later Onan twins using a carb with accelerator pump.  When manufacturing was moved to Canada all the engines featured lean burn and accelerator pumps.  I prefer the older style carb with richer jetting and no accelerator pump, but the fuel efficiency difference is noticeable.

Idle speed isn't a factor in acceleration-load as the engine is operating at max rated speed when the clutch is engaged.