On a Carbureated Engine

[SandburRanch]

with a constant speed governor, what is the carburetor throttle plate position at cranking speed? Fully closed - fully open - part way open - depends where the throttle lever is set - I don't know - I don't care - I didn't even know it had a throttle plate. Vote now.:laughing:

 

[638]

All I've ever seen have been wide open. The governer controls the max RPM, not the minimum. If it started out at an idle, would it ever rev up.

 

[oldnslo]

They are spring loaded to full throttle and the governer brings it back to operating RPM.

 

[Jerry/MT]

with a constant speed governor, what is the carburetor throttle plate position at cranking speed? Fully closed - fully open - part way open - depends where the throttle lever is set - I don't know - I don't care - I didn't even know it had a throttle plate. Vote now.:laughing:

Where you set it with the throttle lever because the governor speed is zero so it can't react to engine speed.

 

[Travelover]

They are spring loaded to full throttle and the governer brings it back to operating RPM.

+1 Exactly right

 

[RalphVa]

My Gravely had a hand throttle that set the throttle plate position.

Ralph

 

[Jay4200]

All I've ever seen have been wide open. The governer controls the max RPM, not the minimum. If it started out at an idle, would it ever rev up.

Generally, there are two plates - one controlled by throttle, and one controlled by the governor. So, with the throttle cranked WFO, the throttle place is wide open, while the governor plate modulates with load.

At least that's the way little motors work.

JayC

 

[Chilly807]

Most I've seen have the throttle lever controlling the tension on the governor spring. More tension = higher speed.

Sean

 

[brokenot]

Generally, there are two plates - one controlled by throttle, and one controlled by the governor. So, with the throttle cranked WFO, the throttle place is wide open, while the governor plate modulates with load.

At least that's the way little motors work.

The throttle plate is controlled by the governor directly. The throttle control the operator moves is connected to a linkage with a spring, (or springs), that then is connected to the governor linkage. There aren't two throttle plates, when you move the throttle control to speed up the engine, you're just applying more pull against the governor's operating force allowing the engine to run faster. The governor is always trying to push the throttle plate closed, and moving the throttle control to raise the rpm causes the governor force trying to close the throttle to have to work harder to do so....because the throttle linkage and springs(s) are trying to pull the throttle plate open with more force than when the engine is idling.

When you raise the rpm by moving the throttle, you're just causing the governor force, (trying to close the throttle plate), and spring-loaded throttle control forces, (trying to open the throttle plate), that are opposing each other to "balance" out at a higher rpm.

 

[Travelover]

..........There aren't two throttle plates..............

Right. There is generally a choke plate and a throttle plate. Maybe this is the cause of confusion.