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Briggs 4HP - New Diaphram and Priming Bulb - Will not Prime

glassc's Avatar

Join Date: May 2010
Posts: 27

03-31-12, 05:20 PM   #1  
Briggs 4HP - New Diaphram and Priming Bulb - Will not Prime

I have a 4HP Classic and replaced the diaphram, priming bulb, and fuel filter screen

It will not prime. New bulb right one no doubt. Same for all parts right ones no doubt. The gas will not prime up. The carberator is secure to the tank. I cleaned the carberator jet too. Snaped it back in.

Need some good suggestions to try.

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31YTech's Avatar

Join Date: Feb 2008
Posts: 1,263

03-31-12, 05:55 PM   #2  
Hello glassc,

Did you put the diaphragm on the tank first then the gasket followed with the carb ?

If so take a look at #11 in this diagram and make sure it's not stuck/gummed up;

Disassembly, Cleaning and Repair of Briggs and Stratton Tank-mounted Pulsa-Prime Carburetor

Good Luck

aj-allen's Avatar

Join Date: Nov 2005
Posts: 467

03-31-12, 06:36 PM   #3  
There is also a check valve behind the primer bulb that may be stuck open.

cheese's Avatar
Forum Topic Moderator

Join Date: Jul 2001
Posts: 16,567

03-31-12, 09:05 PM   #4  
I was thinking of the check valve as well. Here's a trick I've learned over the years for that problem. Take the tank/carb assy off the engine, make sure there is sufficient fuel in the tank. Tilt the carb so that you can put gas into the opening at the top of the carb, and have enough settle in it to cover the priming port behind the primer bulb. Press the primer several times, making sure you keep the fuel level high enough in the carb to keep the port covered. This will suck gas into the primer bulb no matter if the valve is stuck or not, and it will flush gas back and forth through that valve and quite often un-stick it.

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God bless!

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