Adding a fuel pump to a Briggs & Stratton engine

   / Adding a fuel pump to a Briggs & Stratton engine #1  

songhunter

Bronze Member
Joined
Nov 18, 2003
Messages
71
Location
Chattanooga, TN
Tractor
New Holland TC18
I'm trying to put a 12.5 hp Briggs and Stratton engine in my John Deere 111 riding lawnmower. The old B&S 11hp engine threw a rod out the side. Anyway, this JD111 model has the fuel tank under the seat, which means the engine will need a fuel pump.

Has anyone ever added a fuel pump to a B&S engine? I know
the fuel pump vacuum hose connects somehow to or at the
valve cover gasket, but the engine I am using to replace it connects the vacuum hose to the carb.

Any help will be greatly appreciated!
 
   / Adding a fuel pump to a Briggs & Stratton engine #2  
What system did the old 11HP use?

Slam
 
   / Adding a fuel pump to a Briggs & Stratton engine
  • Thread Starter
#3  
It used a B&S fuel pump with a fuel input, output, and vacuum input. I've got a rebuild kit for it. The old valve cover had a single hole and a single hose coming from it going to the vacuum input on the fuel pump. I don't think it had any hose going from the valve cover to the carb.

I don't know whether I should block the carb off and connect the hose to the fuel pump or tap another hole in the valve cover. I'd like to look at an engine that had a fuel pump, but I haven't found one around here.
 
   / Adding a fuel pump to a Briggs & Stratton engine #4  
Would an electric fuel pump work wired through the ignition switch?
 
   / Adding a fuel pump to a Briggs & Stratton engine #5  
Joe, you and I are thinking along the same lines. I have yet to find an electric from my distributor that is small enough. I am still looking.

Slam
 
   / Adding a fuel pump to a Briggs & Stratton engine
  • Thread Starter
#6  
www.jackssmallengine.com has an electric fuel pump, but it's $110. If I'm going to invest that much, I'd rather buy a used Kohler engine off Ebay with the fuel pump already on it.

I really didn't expect it to be this much of a problem. It looks like all I would need is the valve cover that has the two holes in it, one for the fuel pump and one for the carb. I can't find any information on it on the web. JD's website gives a detailed schematic of the original engine, but it doesn't give a part number for the valve cover. /forums/images/graemlins/tongue.gif
 
   / Adding a fuel pump to a Briggs & Stratton engine #7  
The problem with any type of fuel pump is going to be too much pressure. Too much pressure will overcome the float. The first thing that comes to my mind is a windshield washer pump. It will have too much volume and pressure and may not be compatable with gasoline/gasahol. You can put a resistor in series with the pump to decrease pressure. Put a 50 ohm potentiometer (pot) in series with it and adjust the power so it will only lift a foot or so over the carb. I have no answer for the compatability. You will have to test for that. Put the pump in a coffee can of gas for a few days and inspect for damage.

There are 12v automotive units that are fairly cheap. The ones I have seen are solinoid type. The solinoid pull a piston back against a spring. The spring strenght determines fuel pressure. You should be able to cut the spring down until you get the right amount of pressure.
 
   / Adding a fuel pump to a Briggs & Stratton engine #8  
If you have a servicing dealer in your area ask him. Not trying to be sarcastic here but that should always be your first step.

Slam
 
   / Adding a fuel pump to a Briggs & Stratton engine #9  
There you go slamman, taking the easy way out. /forums/images/graemlins/wink.gif

I come up with an aproach Rub Goldberg would be proud of and you kill my joy. /forums/images/graemlins/grin.gif
 
   / Adding a fuel pump to a Briggs & Stratton engine
  • Thread Starter
#10  
I think I've found a solution. Briggs and Stratton part #495734 (called a "breather assembly" on the JD website) has two holes. One is for the carb hose, the other is theaded to accept a 1/4" connector. That was the original equipment. I found one at jackssmallengines for about $17. I'm going to give it a shot!
 
 
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