Old 8hp Briggs and Stratton stalls regularly

[Forest#2]

Install a correctly gapped NEW spark plug. (and do not feel bad if it runs ok afterwards)

Yes leave the heads bolts alone for now they have been at rest since 1985 and good chance one or more will twist off. Your description does not warrant taking the head pull chance yet. NO NEED IN CLEANING ON A DEAD HORSE. You need to do some good through basic testing first.

I've got one of them old snappers with the 8-12 hp Briggs. One is manual start only and one is elec and manual.
Is yours both manual and electric crank? (or manual only??????????)
Does yours have the engine kill on the throttle lever?????????????or on a key switch?????????

 

[VegetiveSteam]

In that 2 or so minutes that the engine won't restart, have you checked for spark in that time period?

 

[SeniorCitizen]

The gas tank cap vent may be plugged on a engine that old .

 

[slomo]

Just because you see a spark is meaningless.

THIS is why I prefer the PET-4000.

 

[slomo]

Loose carbon would go out the exhaust port.

It will also flake off and get between the piston and bore.

This is why all engine manufacturers say to pull the head and de-carbon the cylinder/s every say 5 years or example. Check YOUR engine manual for proper info.

 

[slomo]

Have you replaced the spark plug?

Very wise very wise.

 

[Midnightrider1]

Here is a picture of my engine, it is a basic old 8HP pull start engine. I don't think it has a valve cover to take off and measure, I think I'd have to take the head off to get to the valves. There don't appear to be any points, just a coil next to the flywheel that has two wires, one is the spark plug wire, one is the wire you ground to kill the engine.

Fish, I don't mind checking the valve clearances, is there a way to do that on this type of engine without pulling the head off? It doesn't seem to be a gradual problem as it's heating up, it funs fine and then all of a sudden dies.

Upupandaway, it dies after 5-10 minutes and then dies every 1-2 minutes after that when you re-start it. It runs completely smooth until it dies and when it dies it mostly sounds like you turned the key off. Every now and then it will start to die and then recover and run a couple more minutes before dying. I have put an ignition light on it and watched it when it dies and the light shows good ignition as it's stalling.

I'll get some starter fluid and try spraying that in when it stalls and see if it fires.

Hi guys in regards to your problem. I kind of
have the same issue. Only 8hp briggs&stratton horizontal shaft. It ran with
no problem until it ran out of gas. Then when I pulled started it would run for five seconds and shut off. I was using starter fluid. Clean carb. Put it back together and fired it up. Same thing but only now carb is leaking gas out of the gasket. Order parts
Float spring, float,gasket needle valve. Replaced them. Fixed leak on carb. Still
Only run for five seconds. Just verily runs on full choke then dies. Then from experience to start all over from the start on carb 1.5 turns on needle valve. Still wouldn’t run. Pulled head to check valves to make sure sure they close. Cleaned them and sanded them lightly and reinstalled the head. Still same thing. I did the same as you did. I had full choke on it fired kind of. I took the plug out and checked it. It was not wet. Watch a video and found on it that not all briggs &stratton
Start at 1.5 turns some require high number of turns. I had to set my at 2.5 turns for it to run normally. So I believe you might have to set yours higher number of turns instead of 1.5 turns. I would suggest to turn yours in and count to it bottoms out. Then adjust out and add 1/2 turn. If it starts and runs adjust to fine the sweet spot. Mine drove me crazy. I grew up with these Briggs and Stratton 9hp engines. This was a barn burner on my issue.

 

[Douglas Lee]

I agree, if it stops abruptly, it's ignition.
Thanks
Doug Lee
*

 

[Forest#2]

Hi guys in regards to your problem. I kind of
have the same issue. Only 8hp briggs&stratton horizontal shaft. It ran with
no problem until it ran out of gas. Then when I pulled started it would run for five seconds and shut off. I was using starter fluid. Clean carb. Put it back together and fired it up. Same thing but only now carb is leaking gas out of the gasket. Order parts
Float spring, float,gasket needle valve. Replaced them. Fixed leak on carb. Still
Only run for five seconds. Just verily runs on full choke then dies. Then from experience to start all over from the start on carb 1.5 turns on needle valve. Still wouldn’t run. Pulled head to check valves to make sure sure they close. Cleaned them and sanded them lightly and reinstalled the head. Still same thing. I did the same as you did. I had full choke on it fired kind of. I took the plug out and checked it. It was not wet. Watch a video and found on it that not all briggs &stratton
Start at 1.5 turns some require high number of turns. I had to set my at 2.5 turns for it to run normally. So I believe you might have to set yours higher number of turns instead of 1.5 turns. I would suggest to turn yours in and count to it bottoms out. Then adjust out and add 1/2 turn. If it starts and runs adjust to fine the sweet spot. Mine drove me crazy. I grew up with these Briggs and Stratton 9hp engines. This was a barn burner on my issue.

You will get better responses if you start your own thread. the original posted has ghosted us.

Post up the Model, type and code of the engine.