Briggs Engine 7.75hp - popping, stalling - Snow Blower

Can you give us the model and type number?

Start by checking the valve clearances. It is an OHV which tends to open the valves clearances.
 
Intake Valve.004-.006 in (.10-.15 mm)
Exhaust Valve.009-.011 in (.23-.28 mm

The valves both measure exactly in spec so we're good there.
 
After I checked the clearance, I re-installed the valve cover and tried to run it again with a fresh tank of 93 octane.
 
Here is what I found.
 
It does take some time to start using the electric starter. When it does start, it will only run with the choke 1-2 clicks from fully closed and with the throttle set to WOT. I can see the governor arm moving to open the throttle blade at the carb while cranking. When it does start, the governor arm backs off slightly.
 
When it's running, the muffler seems to get much hotter and faster than it should. With that, I noticed that the side of the plastic gas tank was slightly melted. Not sure if this could mean that there is an ignition timing issue. The previous owner only said that it started to pop while running and he gave up on it.
 
When it does start, if I try to lower the throttle or open to choke, it will pop then shut off.
 
I also hooked up an in-line spark checker while running and the spark never dies while the engine is running.
 
Here is a quick video I took to show what I mean about the choke. The throttle is set to full which is supposed to be 3700 rpm. It doesn't sound like 3700 rpm to me?
 
EDIT: Doesn't look like I can share links. Go to Youtube and paste /watch?v=D0fvf8BqgWI

It does seem like it is running extremely lean. What worries me more is how hot the muffler gets and so fast. 
 
As far as the carb, that is the part number I received. I just checked the box and it does list 798917 as the part number. The gas tank seems to have a nice steady flow leading down to the carb as well. One thing to note is the engine ran the same with the old carb and the new OEM one that's on the engine now.

Does anyone know if anything can cause ignition timing to change or is it fixed?
 
As far as an update, I did a compression checking. Using the electric starter, compression is 120 psi.

Do know the easiest or best way to check the ACR or cam function? While I had the valve cover over, I did spin the engine over by hand and with the starter. The valve train appears to function smooth for what it's worth. Should I plan on tearing the engine down at this point?
 
I've been looking for a factory repair manual but cannot locate one. Anyone know where to find one?

Thanks a bunch for the manual link. I browsed through it and it looks like it's probably the one I need.
 
I help my fingers on the push rod side of the rocker arms while pulling the starting cord and don't recall feeling that. I'll pull the valve cover this evening and check again. If that is in fact the issue, will it be best to remove the engine from the snow blower frame? Not sure how much needs to come apart.
 
As well, if the ACR is screwed up, could that cause the running issues I'm describing?

Ok, sounds good. I'll pop the valve cover off again and check for the bump you describe.
 
It's definitely an odd issue. Most of the small engine stuff I've run into is runs fine or doesn't run. This is somewhere in the middle. I'll post results when I have more information.

I absolutely agree. I will take a video of it running tonight to clearly illustrate the issue. That way we have a good foundation from initial issue to resolution.

The alternator has nothing to do with the way the engine runs, it only powers the light and the heated grips if so equipped. A failed ACR won't affect running but will cause hard starting, the engine will kick back when the rope is pulled or stall the electric starter. Everything you say points to fuel starvation.