riding mower stalls out, runs well after 20 min wait, why?

Question

27HP Briggs Stratton engine. Starts up fine and runs well usually. Twice it has started running then putters out, It will start right back up if I try then putter out again. If I wait an hour it will start and run fine?

Answer 1

Its not the coil......, If it was a coil, it would cut right out when the engine got hot, and in under 5 minutes after it cools down a little, start right back up till it heats up again.

It does sound like a bad venting gas cap (try it without it or have it loose to see if it makes a difference) Or a plugged gas line/fuel filter (note some tanks may have a mesh screen in the tank)

Answer 2

Yea...it's the coil. When a bad coil heats up, the windings seperate. When it cools down, it's back to normal as if nothing was wrong.
If you want to check the gas cap vent - when it stops running, remove the cap and try running it. If the problem remains, then the cap is OK.

Answer 3

One of two things:

A) gas cap vent not working causing the tank to vaporlock.

B) Fuel filter plugged restricting gas flow to carb.


ADDED:
It's not ignition related!!
It it was you would have to wait for the engine to cool for half hour or so. Plus the twin cylider OHV engines have TWO coils, and both of them would not go out at the same exact time.

Answer 4

If this is an old mower than the engine is on its last legs. Heat expansion and contraction of the steel piston rings within the piston bore. Fix it or kill it.

Answer 5

Sounds like the carb is getting flooded. Try to turn down the fuel screw

Answer 6

that is happens because the coil cuts out time to replace it

Answer 7

u either flooded by puttin too much gas into it at one time or mowed when there was too much wet grass.