Likely a clean of the carb paying close attention to the float to ensure it hasn't got fuel inside of it and installing a new float valve. Also install a new bowl mating gasket if you had damaged the old one. These you can split the carb while still mounted to the engine easy enough if you are up for the task. Briggs has online parts diagrams which would help.

Here is a link that might be useful: Briggs parts

I think you may have a fuel starvation problem, not a flood condition.
Clean the fuel system from the tank through the carb. With a older tractor you may have varnish chips stoppng the fuel filter (if there is one), or varnish chips plugging the jets, check the float jet first.
Good Luck

Also, check the rubber hose running from the fuel pump to the crankcase of the engine to ensure that there is not a vacuum leak. This operates the fuel pump.

I didn't look up the model number so don't know if you have an adjustable main jet or not. It will be located on the lower right hand side of the carb sticking up at an angle. Turn counter clockwise 1/8 turn if it does. Anyway, there will be a hex head plug there if not a adjustment screw. I would remove this first thing and see if a bunch of crape runs out with the gasoline. Take necessary gasoline precautions. There will be a low speed mixture adjustment screw looking straight out at you at the back of the carb when you are facing the carb. Might try opening this 1/8 turn and see if it helps.

I would be very careful removing the top of the carb, the gasket needs to come off with the top. IF you damage this gasket, a replacement will be hard to find without buying the complete carb overhaul kit. There are three different versions of this gasket which look alike but have subtle differences.

IF you do remove the top of the carb, blow out the holes looking up in the carb body especially the one that looks like a pc of brass with a hole in it.

Walt Conner

Thanks for the help everyone. I just picked up a carb kit from my briggs dealer gona try it tonight. A guy at work said it could be a loose valve seat? Any ideas? Figure ill try a carb kit new plugs a new fuel filter and a new air filter and go from there.

A loose valve seat wouldn't magically get tight for 2 minutes after cooling.
DID you change the fuel filter? That could EASILY be the problem!

"A guy at work said it could be a loose valve seat?"

These engines will run quit nicely on one cylinder. Of course, they do not have much power that way but do not need choking or any special attention to keep running while not under load.

Walt Conner

After a bit more thought, a bad fuel pump could also cause the problem.
The fact you have to manually close the throttle plate to get it to start infers it's getting too much air for the available fuel.
In a nutshell, fuel delivery through the carb.
Anything from a restricted flow to the pump, through the pump and through the carb would be suspect IMO.

Well all of you that said fuel pump, you were right. I took the carb apart to rebuild it. Dirty but nothing horrible. So I went to take apart the fuel pump, and it was missing the big spring. So I rebuilt the pump and put it all together and ran perfect, no stumbles or any thing. One problem thought, when i throttle all the way up it dosnt seem to be running fast enought. but when i loosen up the governor it revs to the moon and i half to quickly shut it down. Any ideas? I messed with the ideal stop and the jet. thanks for all the help.

How did you measure the RPM?
As you;ve found out, messing with the governor can be tricky.

The IPL lists 5 different governor springs for that engine, with your type# being the "White" one.
I have no idea what colors equal what speeds. I wish I had a chart.

"One problem thought, when i throttle all the way up it dosnt seem to be running fast enought. but when i loosen up the governor it revs to the moon and i half to quickly shut it down. Any ideas?"

IF you loosened the governor arm where it clamps to the shaft coming out the side of the engine, you need to adjust the "static governor setting". There is only one right setting for this. Your top speed can be adjusted by using different springs or in most cases, there are several holes in the arm of the lineage where the spring can be attached. This will vary the range of rpm.

Walt Conner

I'm still trying to start a 422707 motor. I put a fuel pump kit on it. It started once and almost twice, when it turned and fired the gas I added to the carb, but it only ran a few seconds. It doesn't spin fast enough, (if at all), to start, even with a jumper cable to my truck, unless I take out a plug.
I don't understand the vacuum line to the pump, it's a good hose but when blown into, the air blows freely.

Last weekend I got it started, I cut grass for a half hour, but with the choke pulled tight, it didn't have enough power for thick grass, where it died. The new spindles and blades worked well though. Today I added the pump kit. I'm probably ruining the starter trying it so many times.
I suppose a valve job to get it to spin?

"I don't understand the vacuum line to the pump, it's a good hose but when blown into, the air blows freely"

Which direction?

You need to clean the carb Main Jet.
Go to the Briggs site and download the IPL for your engine.
It's REF 117.

http://www.briggsandstratton.com/maint_repair/manual_and_more/

Thanks! I removed the hose from the hose from the fuel pump and blew into that end with my mouth. I hope I put it back on the right nipple (bottom).

The "main Jet", will I need a carb kit, or do I use air or a needle to clean it?

Sorry to be so dumb.

I'm off to the link and then to work.

See my post about 3 down. I would add to use "tag" wire to probe the orifices. Tag wire is the thin wire used to tie on shipping tags.

Walt Conner

Help! I have a 422707 (type 1510 01)opposed 18hp too. I took my carb off because I wasn't getting enough fuel in my carb. It was starving. When I took it off a spring shot off the upper choke butterfly and I'm not sure where it attaches. I contacted B&S and they told me it was too complicated to just post. Their IPL does show the part, but not where the ends connect. Does anyone have a picture of this carb completely hooked up all the way to the governor? Any help would be appreciated.

Another question too. When I took this off I was very careful and saved all the gaskets. Are these the gaskets that can't be reused? They look like the metal compressor type. Do you put any sealant or grease on them when putting the carb back together? Is there a torque that should be used to do this? My first attempt, but I'm an engineer and have rebuilt the rest of this mower I was given for free, hopefully I can do this too.