Adding a fuel pump to a Briggs & Stratton engine

[songhunter]

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!

 

[slammer]

What system did the old 11HP use?

Slam

 

[songhunter]

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.

 

[Joe1]

Would an electric fuel pump work wired through the ignition switch?

 

[slammer]

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

 

[songhunter]

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

 

[Charlie_in_TX]

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.

 

[slammer]

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

 

[Charlie_in_TX]

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

 

[songhunter]

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!

 

[slammer]

(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 )

Sorry about that! I thought your idea was uh....interesting! Yeah! That's it interesting! /forums/images/graemlins/grin.gif

Songman, good luck with it, let us know how it goes.

Slam

 

[songhunter]

Good news! The Briggs & Stratton breather assembly (I've always heard it called valve cover) did the trick. It took the vendor almost a month to get the part in, but it worked great! The breather assemby has a threaded port at the bottom that accepts a 1/4" fine thread nipple. I connected a 1/4" fuel line to it and the pressure side of the B&S fuel pump. The engine started the first time! I could see the fuel being aspirated through the fuel filter.

Thanks folks!

 

[slammer]

Yeehah! Great news buddy.

Slam

 

[TKMAN55]

It is possible to install an electric fuel pump on a small gas engine. Amazon.com sells one for fairly cheap. you will need to add a fuel regulator and set it to about 3psi to keep the float seat from been pushed out. just hook it into your key switch in any "on" power position and keep it on the clean side of your fuel filter. The regulator goes inbetween the carb and the pump.

In the 70s truck refrigeration systems used small gas engines to run the refrigeration compressors. because of the distance and height of the engine from the fuel tank a electric fuel pump and regulator were used.

 

[greenvan]

i also want to put a 12.5 briggs on a jd 111 but my fuel tank is under hood. can it be raised up enough to clear engine properly. 12.5 is abt. 1 in taller

 

[phtann3]

do you have a part number from jacks? I am installing a vanguard -twin on a simplicity baron and am having similar problems. also don't know exactly which wires go where.

 

[sox3]

do you have a part number from jacks? I am installing a vanguard -twin on a simplicity baron and am having similar problems. also don't know exactly which wires go where.

You can go to Stens co and get a vacuum operated pump for about 27 bucks.

 

[phtann3]

thanks I have a pump but don't know where to find vacuum to hook it up. But if this pump doesn't work then I will know where to find one.
can I drill a hole in the valve cover and install a nipple?

 

[sox3]

yes, valve cover, top of block, some have a spot for them already.

 

[gwmartin1945]

I trying to install a 17hp oh vale briggs motor on a toro zrow turn and the fuel tank is 12'' below the carborator and the 17hp briggs does not have a place for the vacum hose what can I do? please help,Wayne