# 18 hp briggs wont start



## curley4270 (Apr 13, 2005)

I picked up a say late 80's craftsman rider 18 hp tractor today . It turns over fine but can't get it running. Replaced the plugs , but took one out and it is staying dry even after I cranked it over. Also tried starting fruid and no luck . Battery is new . 
What is the best way for a novest like me to see if I am getting SPARK ???

Also has a new(less than 1 year) carb on it . The gentleman I got it from said it ran fine last year and just wouldn't start this year . 
Is it a fuel pump that went bad ? I think I see it mounted on the wall , but there is also a small box on the side of the carb ????

BRIGGS & STRATTON MODEL 422437
TYPE 0750 01
CODE 87032612

What do you think I should try next ????


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## bbnissan (Nov 7, 2004)

To answer your question...it is possible that the fuel pump went bad, but on these engines it's more likely a fuel line that has a crack or hole in it. When there is a small crack or hole in the line, the fuel pump cannot create enough vacuum to draw fuel from the tank to the carb.

The easiest way to test the fuel pump is to remove the drain plug from the side of the carb and drain all of the gas out of the carb. After this, reinstall the plug and turn the engine over 5 or 6 times, then remove the plug again to see if the carb filled back up with gas. If it filled up with gas, the fuel pump is good, if it didn't you probably have a cracked fuel line or possibly a bad fuel pump.

You can test the fuel line from disconnecting it from the carb and the tank and then try to blow air through the tank side while holding your finger over the carb side. If you notice an air leak, you need to replace the line.

The easiest way to test the for a spark is to remove the spark plug from one cylinder, keep the plug wire connected to it, then ground the plug on the block while someone else turns the engine over. I recommend you doing this by holding the plug wire with insulated pliers or you will get a good jolt. When you turn the engine over, you should be able to watch the spark jump between the electrodes of the spark plug. If it doesn't, you may have a kill wire that is shorting out, a problem with the safety interlock switches (most likely problem), or a bad coil.


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## curley4270 (Apr 13, 2005)

OK, checked for spark today and all seems good there. Replaced the fuel line (it was cracked at spots) and it is all good there. Still wont start . Turns over , opened the drain plug on the side of the carb and it was completely EMPTY !!! Cranked her over again thinking the fuel line was dry due to changing it and it was still empty . Fuel pump ??? or maybe something else first??? Thanks in advance ,
CURLEY4270


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## curley4270 (Apr 13, 2005)

replaced the plugs , and got her to fire a few seconds with starting fruid. Still the carb is empty so I guess I have a fuel delivery problem. Does it have to be the fuel pump ? And can I use a rebuild kit to fix this problem ??? Thanks


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## curley4270 (Apr 13, 2005)

i keep thinking of thing to ask . Is this suppost to be an electric fuel pump ?? If not how does it work ? There are no wires to it . Just an in line , an out line and a fuel return line(I am guessing) . Thats it


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## mikemerritt (Dec 6, 2004)

Its a vacuum pump. It has an IN, OUT and the other is the vacuum line. The pump is on the front of the carb and is easily rebuilt. The kit is cheap and the only trouble spot is there are two TINY springs that must be put back exactly as they come out. A full kit will have new springs and a diaphragm kit will only have the gaskets etc. 

Mike


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## bbnissan (Nov 7, 2004)

Yeah...just like mike said...make sure you keep track of the springs. They are tiny little boogers that will get away from you in a hurry.


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## curley4270 (Apr 13, 2005)

if that is the fuel pump , what is before the fuel pump ??? the fuel line goes in and out the other side, to the carb , then there is a return line to the thing I thought was the fuel pump ???


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## mikemerritt (Dec 6, 2004)

I was thinking (imagine that) about our descriptions of this pump which are a little off. The 400,000 line only has an input because it gets its pulse from the carb. Since its mounted on the carb there is no OUT. Which leads me to just what are you looking at that has 3 hoses. Here is a cheesy screen shot of your carb and pump. 










Mike


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## curley4270 (Apr 13, 2005)

ok , so what does the fuel line go into before it gets to the fuel pump that is mounted on the carb. is it foroverflow of fuel or what , im sorta lost again , what a suprise huh


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