This anti-backfire Solenoid look okay to you?

[SnapperOwner]

B&S Vanguard V-Twin 23hp
Model 386777
Type 0111-E1
Code 0705241
Part 2690752
Purchased February 2009
Snapper YT2350 YT400 Series 50" Lawn Tractor (aka Riding Mower)

Just a person trying to get the family mower to work again after abuse/neglect. I appreciate all advice.

Been at this a while, and getting discouraged. TK carb. The video is the mower idling at about 1340 (needs to be closer to 1200). Chugs and surges like we aren't giving it enough gas (worse sounding in real life). If we push the throttle plate against the idle screw, it chugs even worse and then dies in about 5-10 seconds. When we took the air filter off this time, there was gas running down from the bottom mount hole. The idle screw works (raises/lowers RPMs) without the plate against it. The two idle mix screws don't make any difference at all. (That's white reflective tape for the tach on the flywheel screen.)

The same engine running WOT sits at about 3400 (should be around 3600). Has a little bit of a surge, but nothing like what happens when you lower it to half-throttle or less. The tach stays pretty steady at around 3450-3500.

Read somewhere that it might be the anti-backfire solenoid that's gone bad. For what it's worth, I've seen this carb removed 4-5 times by just unscrewing the carb (and the solenoid's wires, of course), until the solenoid unscrewed from the carb. (Spews gas everywhere -- there's got to be a better way.) You can see in the photo that there are two stray wires sticking out of the wire sheathcasing at the bottom of the solenoid that look like they might have just broken off. Am I over-reacting? Is that okay like that? Could this cause the surging problems? Am I on the right track here, or do I need to keep looking?

I really need help. A new machine or engine is not in our budget. If it's DOA, then we'll keep mowing the two acres with the weedeater for a while.

 

[Scrubcadet10]

If the engine runs good at full throttle i don't believe the Anti Afterfire solenoid is the culprit, as it blocks off the main jet. How does it run if you engage the blades at full throttle?
it sounds to me like the carb is in need a good cleaning/soaking.

 

[SnapperOwner]

So those wires sticking out like that look all right to you? Even if they aren't the reason for the surging and stalling, do you think it's okay to ignore them?

Carb's been cleaned (off the machine) twice already. Maybe I need to do it again. Ooooof.

Have no idea how it runs with the PTO on. It was stalling with any load on it (two months ago), so we removed the deck and are trying to get a steady idle on it. With no success, so far. I'm working off the Briggs Manual for how to set the carb adjustments, and they want it done at 1200 on Low with the throttle plate held against the screw. Unfortunately, it just stalls when we try that.

Just noticed that the spark plug boots are pretty shot (small cracks all over the part you pull on). I'm going to replace them, but does anyone think that's affecting the roughness and surging?

 

[Richard Milhous]

So those wires sticking out like that look all right to you? Even if they aren't the reason for the surging and stalling, do you think it's okay to ignore them?

Carb's been cleaned (off the machine) twice already. Maybe I need to do it again. Ooooof.

Have no idea how it runs with the PTO on. It was stalling with any load on it (two months ago), so we removed the deck and are trying to get a steady idle on it. With no success, so far. I'm working off the Briggs Manual for how to set the carb adjustments, and they want it done at 1200 on Low with the throttle plate held against the screw. Unfortunately, it just stalls when we try that.

Just noticed that the spark plug boots are pretty shot (small cracks all over the part you pull on). I'm going to replace them, but does anyone think that's affecting the roughness and surging?

If the boots are close to metal, maybe. I've had mowers run fine without any boot at all. But if the boots are in that condition, what is the plug wire insulation like?

 

[bertsmobile1]

So those wires sticking out like that look all right to you? Even if they aren't the reason for the surging and stalling, do you think it's okay to ignore them?

Carb's been cleaned (off the machine) twice already. Maybe I need to do it again. Ooooof.

Have no idea how it runs with the PTO on. It was stalling with any load on it (two months ago), so we removed the deck and are trying to get a steady idle on it. With no success, so far. I'm working off the Briggs Manual for how to set the carb adjustments, and they want it done at 1200 on Low with the throttle plate held against the screw. Unfortunately, it just stalls when we try that.

Just noticed that the spark plug boots are pretty shot (small cracks all over the part you pull on). I'm going to replace them, but does anyone think that's affecting the roughness and surging?

No
But if the solenoid was working and the wires broken then the engine would not run.
You will probably find the plunger has been snipped off because cleaning it can take 2 to 30 minutes and snipping it off takes 15 seconds .
Surging is always a lean fuel problem so it is time to pull the carb , pull it apart & clean it according to the instructions you will find on the outdoorpowerinfo site
You would be well served to do a rebuild while it is apart .
Go to the B & S web page, download the parts book then order the repair kit for your mower
The bits shown inside the boxes with a number in the top right corner are a kit

 

[VRR.DYNDNS>BIZ]

B&S Vanguard V-Twin 23hp
Model 386777
Type 0111-E1
Code 0705241
Part 2690752
Purchased February 2009
Snapper YT2350 YT400 Series 50" Lawn Tractor (aka Riding Mower)

Just a person trying to get the family mower to work again after abuse/neglect. I appreciate all advice.

Been at this a while, and getting discouraged. TK carb. The video is the mower idling at about 1340 (needs to be closer to 1200). Chugs and surges like we aren't giving it enough gas (worse sounding in real life). If we push the throttle plate against the idle screw, it chugs even worse and then dies in about 5-10 seconds. When we took the air filter off this time, there was gas running down from the bottom mount hole. The idle screw works (raises/lowers RPMs) without the plate against it. The two idle mix screws don't make any difference at all. (That's white reflective tape for the tach on the flywheel screen.)

The same engine running WOT sits at about 3400 (should be around 3600). Has a little bit of a surge, but nothing like what happens when you lower it to half-throttle or less. The tach stays pretty steady at around 3450-3500.

Read somewhere that it might be the anti-backfire solenoid that's gone bad. For what it's worth, I've seen this carb removed 4-5 times by just unscrewing the carb (and the solenoid's wires, of course), until the solenoid unscrewed from the carb. (Spews gas everywhere -- there's got to be a better way.) You can see in the photo that there are two stray wires sticking out of the wire sheathcasing at the bottom of the solenoid that look like they might have just broken off. Am I over-reacting? Is that okay like that? Could this cause the surging problems? Am I on the right track here, or do I need to keep looking?

I really need help. A new machine or engine is not in our budget. If it's DOA, then we'll keep mowing the two acres with the weedeater for a while.

View attachment 58158View attachment 58159

minimum idle speed is 1750 rpm. Do not expect it to run normal below that as it is not designed for that low a carb flow.