B&S 10L802-0858-F1 Run Issue (Auto-choke/Govenor?)

[Rivets]

I’ll try again with the bulletin. https://bsintek.basco.com/BriggsDocumentDisplay/P5.6uIX-nfBhU7y.pdf

 

[nsnd]

Ah perfect. I did follow that procedure; luckily, it was also in the manual you shared with me.

 

[nsnd]

Ripped it apart again and put the other spring in; RPM's back to normal-ish. Also, swapped another new diaphragm with the same results. I took slowmo video and focused on the exhaust and blade (just in case).

 

[Born2Mow]

The easiest way to make an engine run rich is for the choke to be partially ON. As I remember these carbs have sort of an automatic choke setup, so you really can't tell what position it's in. I'm wondering if you can bend an 8" piece of mechanic's wire to force the choke butterfly into a constant full open (or fully OFF) position. 8" is long enough where there's no danger of it being sucked into the engine.

If it runs no better we can rule out the choke.

Apologies if this has already been ruled out.

 

[Scrubcadet10]

The easiest way to make an engine run rich is for the choke to be partially ON. As I remember these carbs have sort of an automatic choke setup, so you really can't tell what position it's in. I'm wondering if you can bend an 8" piece of mechanic's wire to force the choke butterfly into a constant full open (or fully OFF) position. 8" is long enough where there's no danger of it being sucked into the engine.

If it runs no better we can rule out the choke.

Apologies if this has already been ruled out.

No choke. Primer carb.

 

[nsnd]

I notice the throttle is almost always completely open, even during a cold startup. When force the throttle closed, the RPM's increase (which seems counterintuitive to me...) and it starts to run smoother, but still seems to have the rich running appearance.

Top View - Operator Side


Side View - Engine Side

 

[nsnd]

Lawn needed to be mowed today, so I decided to take the mower for a spin. I realized it wasn't running normal RPM's (so my tach is definitely off; @Richard320 :-D). I noticed there was very little air movement from the blade, which is in good shape. I fixed the throttle open by removing the governor spring and used a piece of copper wire to hold it in a fixed position. It ran better and stopped spitting smoke.

However, even with the throttle in a fixed position, I couldn't get the RPM's to step up without the mower trying to die. Going to take a break and inspect everything I can see.

 

[Rivets]

The governor spring attaches to a metal plate sticking up, right? This plate needs to be bent outward, lengthening the spring to set the governed top speed. Take a needle nose pliers and slowly bend it away from the carb until yo get the speed you need. Bending it in will slow the engine speed.

 

[nsnd]

The governor spring attaches to a metal plate sticking up, right? This plate needs to be bent outward, lengthening the spring to set the governed top speed. Take a needle nose pliers and slowly bend it away from the carb until yo get the speed you need. Bending it in will slow the engine speed.

I gave it a shot, but the throttle stays completely open (see my picture labeled: Top View - Operator Side). I have to forcefully work against the spring (close the throttle) to get it running better (stop running rich and increase RPM's).

Since I previously messed up the governor, I followed the instructions in this video to reset it:

. The mechanical governor had absolutely no pressure applied. Same results though: throttle stays completely open while running. (Side note: I accidently set the governor with the throttle closed. I re-adjusted to have the throttle open instead.)

What's the best way to check that mechanical governor, take apart the engine?