Found the CURE!

There have been several threads on here about Briggs and Stratton "V"- Tech engines not running well. Went back and found Flying Belgian and 4435 for a couple. I have two machines with 21 and 22 hp engines on them. Had to rebuild the carb on one and found out all about the fuel jets and tiny "O" rings and on and on. Another thing is behind that black plastic block in front of the choke plate with the four little holes the fiber gasket swells up and the holes get choked off. Well a couple of days ago I was mowing with my big Husqvarna machine and all of a sudden it is running on one cylinder. Runs rough. The fastest check you can do is pop off the air filter top and remove the filter. Take a pump can with a little gas in it and with the motor running pump a squirt or two all of the way to one side of the air passage. If no change squirt the other side. All of a sudden the engine is now running on two cylinders for a second or two. You have carb problems. What is going on is these Nikki carbs are a closed loop balanced carb "have read this description several times", and when they goof up you now have 1/2 the gas to one cylinder and 1 1/2 going to the other cylinder. If you pull the plugs one is nice and clean and the other is all sooty. You can actually smell the one cylinder is running rich.
Here is where I found a BIG difference! I finally don't want to rebuild a carb again and went on flebay and bought a new carb. Take a look at item 331888382450 or any of the others listed. This is a THIRD revision carb and for about $115.oo it is a bargain! These are the ones built in Japan and it is the one you want.
Installed the new one on my machine and started her up .
MAGIC WAND TIME!!!!!!! Everything works like a magic pixie has blessed my engine. Beautiful smooth low idle, instant rev-up to speed and right back to idle. When going from lite grass to super heavy mowing the motor doesn't even change in sound never mind speed it just keeps going! EVERYTHING WORKS!!!!
Sounds like I am happy? Was it 4435 with the Zero turn? Go get one for your Zero turn. Fantastic carb! I would say it is like an engine with a crummy carb to an engine with electronic fuel injection! No kidding! Worth every penny. Total beauty.

PS. use all of the gaskets that come in the pack where they need to go! New ones for the manifold to the block. Makes for a bit of a snug fit. Also that air mixer plate. Follow the directions.

Thanks Jeff. Mine does not have that black plastic 4 hole block like I see in your pic, nor does it have the solenoid. Buttttt I will get my part number tomorrow and do some looking.
I increased the jet sizes on mine to the next larger engine. Yes it runs a little rich and is still kinda gutless. Especially compared to the opposed p220G onan. Tom

Glad you got back to me! Didn't you say you had a Briggs twin? Don't know but I have looked at least a dozen engines in two guys repair shops and some were set up like mine. Oh well what ever they screwed into the machine. The number you need is right on the carb in little tiny numbers and letters on the flange. I thought everything had a shutoff now a days. Well I hope I helped cause the newer generation on my machine is magic. Cross your fingers and buy a new one. Get back to us. By the way I have found a lot of people do NOT know how to set the governor correctly. The directions are MUDDY at best but read over them several times and look at the engine and sooner or later you figure it out. What I did is this. Throttle all of the way, push the rod over to the side and hold it with your pinky, lossen the clamp and turn the shaft counter, THEN tighten the clamp. You need to hold everything in the positions they need to be cause they will move. The governor is very touchy on these engines. I down loaded all of the pages so you can read them and scratch your head too. Thanks Jeffcat

AWWW nuts! these were all hi res when I down loaded them. Hope you can make them out.

Thanks for the try Jeff. I reviewed my service manual, Looks like I got the governor set right. My Carb is #808278 still at a couple hundred on ebay for a replacement. So I think to hold of for now. Tom

Thanks for the tip. I bookmarked your thread for future reference.