| Author |
Chraftsman 18hp. twin fuel problem
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| We have an 18 hp. twin fuel pump on the side of the carb . It was
working fine and then quit . It appeared that it was lack of gas as it
would start and run as long as you pored the gas in the carb . I
rebuilt the fuel pump and it still wasn't getting fuel . I took the
top off the carb and it was bone dry . I replaced the needle valve and
it still didn't get fuel . This time when the carb was apart I pored
some gas in the bowl and pored gas to the fuel pump line doing it
several times and turning it over to prime the pump . When I put the
carb back together it started right up and ran good . I took it out to
try mowing with it an again after about 10 minutes it acted like it
was starving for gas . Then it stalled again . Same problem . The fuel
pump seems to be powered by a vacum hose coming up from the
crankcase . Is there anything in the crankcase (filter)or something
that would plug up ? I can feel som air coming out of the hose when I
turn it over . I can suck fuel out of the gas line at the fuel pump
connection from the tank...Any ideas...Rick
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| Srgnt Billko 2007-06-07, 5:25 pm |
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"Rick" <techforce5@gmail.com> wrote in message
news:1181235327.353153.109070@w5g2000hsg.googlegroups.com...
> We have an 18 hp. twin fuel pump on the side of the carb . It was
> working fine and then quit . It appeared that it was lack of gas as it
> would start and run as long as you pored the gas in the carb . I
> rebuilt the fuel pump and it still wasn't getting fuel . I took the
> top off the carb and it was bone dry . I replaced the needle valve and
> it still didn't get fuel . This time when the carb was apart I pored
> some gas in the bowl and pored gas to the fuel pump line doing it
> several times and turning it over to prime the pump . When I put the
> carb back together it started right up and ran good . I took it out to
> try mowing with it an again after about 10 minutes it acted like it
> was starving for gas . Then it stalled again . Same problem . The fuel
> pump seems to be powered by a vacum hose coming up from the
> crankcase . Is there anything in the crankcase (filter)or something
> that would plug up ? I can feel som air coming out of the hose when I
> turn it over . I can suck fuel out of the gas line at the fuel pump
> connection from the tank...Any ideas...Rick
I don't screw around - I go to NAPA and get a low pressure electric fuel
pump and install that. I haven't had to remove the old diaghram pumps yet -
but when the tanks are low and in the rear I mount the electric pump back
there. The one I installed a couple weeks ago I ran from the light switch
that was no longer used so I can shut it on and off. Others I have right
from the ignition switch.
>
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| Rick wrote:
> We have an 18 hp. twin fuel pump on the side of the carb . It was
> working fine and then quit . It appeared that it was lack of gas as it
> would start and run as long as you pored the gas in the carb . I
> rebuilt the fuel pump and it still wasn't getting fuel . I took the
> top off the carb and it was bone dry . I replaced the needle valve and
> it still didn't get fuel . This time when the carb was apart I pored
> some gas in the bowl and pored gas to the fuel pump line doing it
> several times and turning it over to prime the pump . When I put the
> carb back together it started right up and ran good . I took it out to
> try mowing with it an again after about 10 minutes it acted like it
> was starving for gas . Then it stalled again . Same problem . The fuel
> pump seems to be powered by a vacum hose coming up from the
> crankcase . Is there anything in the crankcase (filter)or something
> that would plug up ? I can feel som air coming out of the hose when I
> turn it over . I can suck fuel out of the gas line at the fuel pump
> connection from the tank...Any ideas...Rick
>
That pump works off of alternating pressure and vacuum from the
crankcase. They do not develop much pressure at all. I've never seen a
pulse line get plugged. When you rebuilt the fuel pump did you clean
every speck of the old gaskets off? I usually run a flat file over the
pump body and cover lightly several times to make sure it is clean and
flat. The thin rubber diaphragm goes against the body, then the gasket,
then the cover.
Check the pickup in the bottom of the tank, many have screens, and clean
as needed. If there is an in-line fuel filter replace it with one from a
small engine shop. Do not use an automotive or paper type fuel filter.
That pump will not develop enough pressure to get the fuel through it.
Also check the fuel line. If it is cracking at the ends or is soft and
squishy, replace it. Also check that the fuel cap is vented.
You are on the right track. Good luck.
--
Art
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| Srgnt Billko wrote:
> "Rick" <techforce5@gmail.com> wrote in message
> news:1181235327.353153.109070@w5g2000hsg.googlegroups.com...
>
> I don't screw around - I go to NAPA and get a low pressure electric fuel
> pump and install that. I haven't had to remove the old diaghram pumps yet -
> but when the tanks are low and in the rear I mount the electric pump back
> there. The one I installed a couple weeks ago I ran from the light switch
> that was no longer used so I can shut it on and off. Others I have right
> from the ignition switch.
>
>
I've never done that. Have you ever had any problems with the carb
flooding? My concern is that even a low pressure electric pump might
overcome the pressure on the needle from the float.
--
Art
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| On Jun 7, 4:26 pm, "Srgnt Billko" <f...@blipl.net> wrote:
> "Rick" <techfor...@gmail.com> wrote in message
>
> news:1181235327.353153.109070@w5g2000hsg.googlegroups.com...
>
>
>
>
>
>
> I don't screw around - I go to NAPA and get a low pressure electricfuel
> pump and install that. I haven't had to remove the old diaghram pumps yet -
> but when the tanks are low and in the rear I mount the electric pump back
> there. The one I installed a couple weeks ago I ran from the light switch
> that was no longer used so I can shut it on and off. Others I have right
> from the ignition switch.
>
>
>
> - Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
Thanks for responding , I'm curious , how many LB. pressure pump do
you use . I kind of would like to figure out the problem . It has
worked flawlessly this way for 25 years . Rick
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| On Jun 7, 6:01 pm, Art <Arte...@spamtrap.invalid> wrote:
> Rick wrote:
>
> That pump works off of alternating pressure and vacuum from the
> crankcase. They do not develop much pressure at all. I've never seen a
> pulse line get plugged. When you rebuilt thefuelpump did you clean
> every speck of the old gaskets off? I usually run a flat file over the
> pump body and cover lightly several times to make sure it is clean and
> flat. The thin rubber diaphragm goes against the body, then the gasket,
> then the cover.
> Check the pickup in the bottom of the tank, many have screens, and clean
> as needed. If there is an in-linefuelfilter replace it with one from a
> small engine shop. Do not use an automotive or paper typefuelfilter.
> That pump will not develop enough pressure to get thefuelthrough it.
> Also check thefuelline. If it is cracking at the ends or is soft and
> squishy, replace it. Also check that thefuelcap is vented.
>
> You are on the right track. Good luck.
>
> --
> Art- Hide quoted text -
>
> - Show quoted text -
Thaks for the info, The filter came from Laser Sales (a small engine
supply ) It is clear plastic and the filter media inside looks like a
GM filter (the small ones that go in the carb . I can suck gas through
the line right from the connection at the fuel pump . I light sanded
the surfaces to make sure I had everything . I wasn't aware there was
a pickup screen in the tank . I will check on it . I certainly acts
like the fuel is being restricted . Rick
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| Srgnt Billko 2007-06-07, 8:25 pm |
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"Art" <Artemis@spamtrap.invalid> wrote in message
news:8i%9i.28$IJ2.27@newsfe07.phx...
> Srgnt Billko wrote:
>
> I've never done that. Have you ever had any problems with the carb
> flooding? My concern is that even a low pressure electric pump might
> overcome the pressure on the needle from the float.
>
> --
> Art
No - and my nephew uses the same approach. He buys and sells - I just
collect.
http://mysite.verizon.net/vzet83bg/tractorguy/
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| Srgnt Billko 2007-06-07, 8:25 pm |
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"Rick" <techforce5@gmail.com> wrote in message
news:1181258601.154666.278010@h2g2000hsg.googlegroups.com...
> On Jun 7, 4:26 pm, "Srgnt Billko" <f...@blipl.net> wrote:
>
> Thanks for responding , I'm curious , how many LB. pressure pump do
> you use . I kind of would like to figure out the problem . It has
> worked flawlessly this way for 25 years . Rick
>
I just put one on a 18 HP Briggs twin on a 1984 Agway (Murray). I have one
on a 1960's 70's Sears Suburban 16 HP single (Tecumseh). And I put one on a
1980's Sears twin that I sold. As I said above, my nephew also uses them.
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| Srgnt Billko 2007-06-07, 8:25 pm |
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"Art" <Artemis@spamtrap.invalid> wrote in message
news:9f%9i.26$IJ2.13@newsfe07.phx...
> Rick wrote:
>
> That pump works off of alternating pressure and vacuum from the crankcase.
> They do not develop much pressure at all. I've never seen a pulse line get
> plugged. When you rebuilt the fuel pump did you clean every speck of the
> old gaskets off? I usually run a flat file over the pump body and cover
> lightly several times to make sure it is clean and flat. The thin rubber
> diaphragm goes against the body, then the gasket, then the cover.
> Check the pickup in the bottom of the tank, many have screens, and clean
> as needed. If there is an in-line fuel filter replace it with one from a
> small engine shop. Do not use an automotive or paper type fuel filter.
> That pump will not develop enough pressure to get the fuel through it.
> Also check the fuel line. If it is cracking at the ends or is soft and
> squishy, replace it. Also check that the fuel cap is vented.
>
> You are on the right track. Good luck.
>
> --
> Art
All good advice - especially the file rather than sand paper.
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