Briggs Vanguard CARB / Valve / Throttle issue

Im having a slight issue with this engine. I recently did a valve adjustment. The mower was sometimes hard to start getting over that compression stroke. I am now having a problem throttling the mower up without the choke on. The mower platform is a Simplicity Broadmoor 1694010 and the engine is a 303777-1114-E1 code 01013111. The mower will run on any throttle setting but increasing the throttle from idle sometimes makes the engine stall or hesitate for several seconds before increasing RPM's. If I start the mower on a low speed, and increase the throttle, it seems fine. If I then lower it back to a idle and within 10-15 seconds or lower try to increase it, the engine wants to fall on its face. I replaced the spark plugs and fuel filter last night in hopes those were the issue but it did not solve it. I also too the air filter off completely and removed the gas cap in case the tank was building pressure and not letting in makeup air. I set the valves to .005" on both the exhaust and intake when I did the adjustment. Anyone have any ideas what could be causing this? I am thinking it could be a bad valve spec?

And does anyone know where I could aquire a new carb for this thing? It seems everywhere is showing it now longer available. I really need just the body of the carb itself. At the beginning of last season, I accidentally threaded the bolts into the carb in the wrong hole and caused it to drive through the edge of the casting. It didn't pierce any channel ways or passages so I was able to mend it back up with some JB Weld and it ran perfect all last season. Even going on the Vanguard website and using the part number from a 16HP motor they have listed, the carb is not available. Does this seem correct?

Double check the valve lash.
Even pros occasionally do not tighten the lock screw enough.
Note you adjust the lash with the nut and lock it with the grub screw.
Also check the stud as they have a habit of coming loose.

I checked tonight and tweaked them all very minimally. Push rods are all in the correct locations. It ran fine before the adjustment except for the occasional no start because its stuck on the compression hump. I can rev the motor up with the choke on and it responds to throttle snaps instantly. It doesn't appear to run rough like it would normally do after applying the choke with the engine warm. I pulled the carb and cleaned what i could. I couldnt remove the main jet as the head of the screw busted off. Im starting to think the valve spec I pulled might not be correct?

They look about right.
I use 0.004" for just about all engines because I am lazy & cheap so a loose leaf .004" feeler, cut to some easy fit shapes works well for me.
Running for a long time with excessive valve lash can cause abnormal wear on the cam and excessive wear at full open.
Apart from that it sounds like a blockage in the carb.
Manually move the governor lever to increase the revs overiding the governor.
If it revs cleanly all the way to WFO then you have a governor problem.
In particular the damping spring that sits over the linkage from the throttle to the governor lever.

Then saturate the manifold ares with the engine set to WFO.
If the engine changes speeds or blows white smoke you have a vacuum leak.

bertsmobile1 said:

They look about right.
I use 0.004" for just about all engines because I am lazy & cheap so a loose leaf .004" feeler, cut to some easy fit shapes works well for me.
Running for a long time with excessive valve lash can cause abnormal wear on the cam and excessive wear at full open.
Apart from that it sounds like a blockage in the carb.
Manually move the governor lever to increase the revs overiding the governor.
If it revs cleanly all the way to WFO then you have a governor problem.
In particular the damping spring that sits over the linkage from the throttle to the governor lever.

Then saturate the manifold ares with the engine set to WFO.
If the engine changes speeds or blows white smoke you have a vacuum leak.

Click to expand...

Any idea what the governor setup on this motor should look like? I am reading through the Briggs service manual I pulled off the net and its giving me several styles of governors. I am not sure which mine is. 272144 looks to be the number off the manual.

https://www.briggsandstratton.com/n...ualSearch.html?searchrequested=303777-1114-e1

https://www.ebay.com/itm/Briggs-Stratton-Parts-807708-KIT-CARB-OVERHAUL-BS-807708-/132171774393

https://www.vanguardengines.com/na/en_us/support/faqs/browse/overhauling-the-carburetor.htmlhttps:

https://www.simplicitymfg.com/eu/en_gb/search.html?searchrequested=1694010

This is what it's doing when I take the air filter housing off to inspect it. I haven't been up close to notice it spitting gas back out. Everything with the governor looks good unless someone more knowledgeable here spots it out of place.

Sounds like it may be running on one cylinder.

Not sure what I did but its running perfectly now. I threw everything back together and did a full tune up on it. Oil, oil filter, spark plugs, fuel filter, new air filter and pre filter. I tested to make sure it was running on both. I pulled the plug wires off one at a time and both times it started to stumble.

Thanks for the help everyone! I appreciate it!

Now onto my next project.... a Kawi FJ180v.