I've got a 14.5 I/C B&S engine on a yard machine mower that has been giving me fits. It will start and run great for about 5 minutes then it just stalls out. I was told it was a carb so I put another one on, no luck. Did a new plug and coil. It's getting fuel and spark. Could it just be an overheating problem? Sure has me stumped. I've never had this problem with a B&S. Appreciate any info.
14.5 Briggs & Stratton problem
- Thread starter old8nguy
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Travelover
Elite Member
When it quits, does it have compression? I'm thinking of a hanging valve.
Does it have spark the minute after it quits? Sometimes the coil heats up and opens up. If you shoot gas into the carb just after it quits, will it run momentarily?
Does it have spark the minute after it quits? Sometimes the coil heats up and opens up. If you shoot gas into the carb just after it quits, will it run momentarily?
jhwentworth
Silver Member
In most of the B&S valve problems I've seen the symtom is poor or no starting.
You've replaced the carb, plug, and coil. The coil and plug make up the complete ignition system on this engine. There is an "ignition kill" wire that grounds the coil output, with the ground signal coming from the ignition key and various safety switches (seat, PTO, clutch, etc.). If you remove that ground wire, and it still fails, then it's a fuel problem.
If it's a fuel problem, a possible cause is a lack of fuel tank venting. Try loosening the gas cap and run the machine for 15-20 minutes. I think I might try this first as it's the easiest to do. A partially plugged fuel line will also cause this type of problem. Try removing the fuel line from the fuel filter and blowing compressed air back into the tank (remove fuel cap).
You've replaced the carb, plug, and coil. The coil and plug make up the complete ignition system on this engine. There is an "ignition kill" wire that grounds the coil output, with the ground signal coming from the ignition key and various safety switches (seat, PTO, clutch, etc.). If you remove that ground wire, and it still fails, then it's a fuel problem.
If it's a fuel problem, a possible cause is a lack of fuel tank venting. Try loosening the gas cap and run the machine for 15-20 minutes. I think I might try this first as it's the easiest to do. A partially plugged fuel line will also cause this type of problem. Try removing the fuel line from the fuel filter and blowing compressed air back into the tank (remove fuel cap).
Ken
Veteran Member
Is this the Alum. block with over head valves? if so look carefully at the valve where it seats when closed on a steal ring inserted in the head. This ring sometimes is loose and does not seal to have compression engine runs rough to stalling with load. Or the bolt holding the push rod is loose also.price of replacement head close to replacement engine.
B/S not the engine quality it used to be.
ken
B/S not the engine quality it used to be.
ken
mostly_gas
Super Member
Does the engine have a fuel pump?
