briggs and stratton push mower engine

ACF

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i have a push mower with a 5 hp b/s engine that will not start unless you use starter fluid. i have clean carb replaced primer bulb, air filter base plate, did not resolve the problem still needed starter fluid, so replaced carb, this did not reslove the problem still need starter fluid to get running once running it runs good. any clues as to resolve this problem.
thanks
AC
 

Rivets

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Please post model, type and code numbers for the engine. We are not psychic and hate guessing as to which Briggs engine you are looking at.
 

ACF

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b/s 4.75 hp
model 12L902-0667-E1
serial 0603165
 

Rivets

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With that carb I’m inclined to say your float needle seat has swelled causing a lean starting condition. Recommendation is to remove the carb and replace the float needle and seat, and make sure that you set the float to the proper level.
 

ACF

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installed new
With that carb I’m inclined to say your float needle seat has swelled causing a lean starting condition. Recommendation is to remove the carb and replace the float needle and seat, and make sure that you set the float to the proper level.
installed new carb same problem
 

Rivets

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Did you purchase the new carb off Amazon or FleaBay. If so I would not be surprised that your carb is not good. I always recommend buying OEM from a reputable dealer. My recommendation to you at this point is to take the float bowl off the old carb, tip it upside down and see it the float is either level or slightly down on the side opposite the float pin. If it is I’m wrong, but if it is higher on the opposite side you have a swollen seat.
 

cubs fan

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[ATTACHREUSE]
check your filter base to see if the primer is working
 

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slomo

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i have a push mower with a 5 hp b/s engine that will not start unless you use starter fluid.
Indicates. most likely a fuel delivery issue.
i have clean carb replaced primer bulb, air filter base plate, did not resolve the problem still needed starter fluid, so replaced carb
Did you install new carb gaskets? Over torque the carb mounting screws or air filter base plaste with your impact gun? Check for vacuum leaks?
 

cubs fan

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the next question, if it runs smooth and easy after spraying starter fluid. Sometimes you can find a two cans special at NAPA for starting fluid.
 

StarTech

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Even with a new primer air base you can still have priming problems if it is not sealing properly to the carburetor. Check the gasket impression as to where there is no contact. ANd don't over tighten to screws as they can warp the plastic base.
 
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