# 18hp briggs twin fuel problem



## brokeokie (Apr 13, 2011)

Hey all, It's been awhile since you solved my last troubles and I'm back with a new one.
Troy Built 42" rider
Briggs 18hp Twin II
Model 42A707
Type 2238E1
Code 9908305A

When I started it this year for the first time it ran rough for about a minute and then smoothed out and ran fine for about three hours until my deck belt broke. When I say "fine" I should mention that for the last two summers I've had to run it with the choke a little out to keep it running.
Got the new belt the next weekend and went to start it and nothing. I didn't seem to be drawing any fuel to the carb. If I put fuel directly into the carb it will start and run until it uses the fuel that was poured in.
Checked fuel line and filter and fuel runs freely all the way to the carb. I just rebuilt the carb including the fuel pump diaphragms and got my hopes up that that would fix it but it's still the same.
Any ideas?
Thanks in advance!


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## SmallengineDave (Jun 11, 2012)

*Briggs fuel problem*

Check the fuel soleniod, it should be clicking at least, check for 12volts at the plug in first, if 12 volts, pull soleniod and watch it to see if it retracts, if not replace.


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## brokeokie (Apr 13, 2011)

It doesn't have an elctric selenoid. Just the bowl plug.


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## SmallengineDave (Jun 11, 2012)

*18hp briggs*

Bowl plug on the side?, if so it is the main jet, pull the plug if fuel is in bowl plugged main?, if not fuel pump not working?


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## brokeokie (Apr 13, 2011)

I soaked over night and spent several hours spraying every orafice and replaced jets and blew every thing out with air tank before putting it back together. I replaced pump diaphrams also. If I crank motor with drain plug out shouldn't gas run out? It doen't if so just barely. I agree with the fuel pump but don't know how to fix.
Thanks for the info so far!


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## SmallengineDave (Jun 11, 2012)

Did you replace the rubber diapham in the fuel pump?


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## brokeokie (Apr 13, 2011)

Yes. Starting from the outer metal plate there was a gasket then a solid diaphram then the pump body then a dished diaphram with a metal cup and spring. Every thing went together just like the old ones that were stiff and brittle. I thought that would be the fix.
One thing that I didn't do was drain out all the old gas(only a month old) but like I said before it ran for three hours plus, before the belt broke and it set for a week. I mowed twice before this happened.
I'll start back at square one and drain and cleen the tank and re-check the carb and make sure the gaskets in the re-build kit match the origanal.
Anything else I should look for? 
Again thanks for taking the time to post your replies.


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## RKDOC (Jun 20, 2006)

There are two springs in the fuel pump. Did both get back in place? Also if the fuel lines look cracked, you need to replace them. The slightest air leak will cause this fuel system problems. The fuel lines can be bad even if they don't leak gas.

Best of luck.


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## 30yearTech (Sep 14, 2006)

Make sure fuel is flowing though the fuel lines from the tank to the pump. Today's fuel can really mess up fuel lines, especially older ones.


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## brokeokie (Apr 13, 2011)

Ok RKDOC only one spring is in the fuel pump re-build kit and yes 30 yr tech I'll replace the entire fuel line if you think it will help. I replaced the entire fuel line from the tank to the carb a couple years ago. The only place that might be an if is at the hose clamp at the fuel pump. I'll cut a quarter inch off and reclamp and see what happens.
Thanks Guys for your response!


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## brokeokie (Apr 13, 2011)

RKDOC said:


> There are two springs in the fuel pump. Did both get back in place? Also if the fuel lines look cracked, you need to replace them. The slightest air leak will cause this fuel system problems. The fuel lines can be bad even if they don't leak gas.
> 
> The exploded diagram that came with the re-build kit only showed one spring. Where would the other one be located?
> Thanks


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## RKDOC (Jun 20, 2006)

I went and looked at the IPL for your engine. The pump diaphragm on your fuel pump is different than other carburetors of the same type that I have worked on. Yours shows only having one spring. Sorry for the confusion!!


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## brokeokie (Apr 13, 2011)

Ok guys I'm Confused! The schematic diagram that came with the re-build kit shows the fuel pump as first the outer metal plate then the diaphragm then the pump body then the dished diaphragm then the cup and then the spring. That's what I remember taking it apart. The diagram from the B&S site shows the outer plate then the solid diaphragm then the pump body then the spring then the cup and then the dished diaphragm. I'm sure that the first is right but please tell me if I'm wrong. 
Thanks for the input


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