carbs
08-25-2009, 06:38 AM
#1
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carbs
Hi,
I have two wt 257 carbs in my cat and I was wondering is there a carb with a primer bulb that would be the same.
I cant primer the carb by putting my finger over it as there is no room. I need two carbs with primers. I heard that the wt 644 are the same but with bulbs, is this true?
Also were would I be able to purchase them from?
Regards Peter
I have two wt 257 carbs in my cat and I was wondering is there a carb with a primer bulb that would be the same.
I cant primer the carb by putting my finger over it as there is no room. I need two carbs with primers. I heard that the wt 644 are the same but with bulbs, is this true?
Also were would I be able to purchase them from?
Regards Peter
08-25-2009, 07:26 AM
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RE: carbs
The 644 will also need to be choked the primer bulb is just that, it allow you to get the fuel to the carb, but dosn't choke it. Although the 644 does have a choke built in so using the choke with tube attached you will be able to choke the carb.
I would drop back to the 644 or I belive the 813 has a pump built in and it might work even better. There are other that might add to this as I have never owned the 813.
Good Luck;
Randy
I would drop back to the 644 or I belive the 813 has a pump built in and it might work even better. There are other that might add to this as I have never owned the 813.
Good Luck;
Randy
08-25-2009, 08:22 AM
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RE: carbs
the only way I can start the motors is by pulling the plugs out and adding fuel through the plug hole. Its a real pain so i want a carb that is equivelent to the wt257 but with a primer bulb.
Also is there some were on line I could order them from?
Also is there some were on line I could order them from?
08-25-2009, 09:32 AM
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RE: carbs
ORIGINAL: wetsleeves
the only way I can start the motors is by pulling the plugs out and adding fuel through the plug hole. Its a real pain so i want a carb that is equivelent to the wt257 but with a primer bulb.
Also is there some were on line I could order them from?
the only way I can start the motors is by pulling the plugs out and adding fuel through the plug hole. Its a real pain so i want a carb that is equivelent to the wt257 but with a primer bulb.
Also is there some were on line I could order them from?
www.gizmomotors.com
and several others
08-25-2009, 05:10 PM
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RE: carbs
ORIGINAL: Dan S
The bulb is a primer,
yes it takes the air out of the line, but it primes the carb with fuel.
Dan.
The bulb is a primer,
yes it takes the air out of the line, but it primes the carb with fuel.
Dan.
It does not put any fuel in the throttle bore, which is what is need for starting, to make starting easier you need to have fuel in the throttle bore, the choke on carbs so equipped do that by causing the vacuum from the intake port to draw fuel from the metering chamber into the bore and by restricing the air flow make a rich mixture that is easier to start then engine.
A non choke carb with a air purge bulb will be just as hard to start as a non choke non air purge bulb carb. You have to block the intake to carb to pull fuel from metering chamber or spin it fast enough for the air flow to create the pressue drop in the venturi needed to get fuel into the throttle bore.
Just use the 644 with the choke.
08-25-2009, 05:22 PM
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RE: carbs
The bulb clears the line of air and draws fuel up to the carb from the tank, for must people that is understood as primer bulb. Adding a primer bulb likely won't solve your problem. What might work is adding the 644 with choke. You could also keep what you have and use a plug on the carb intake while pull starting. Once it fires pull the plug out of the carb throat. Use a string or something similar to make it easy to pull out and hard to loose.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
08-25-2009, 05:42 PM
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RE: carbs
The boat is a cto3 with twins, there isnt enough room for me to put my finger over the carbs to prime the fuel into the carb (get the air out of the fuel line) to start the motors, so I was thinking of getting a carb with a primer on it so I can purge the line. It would be good if I could get a wt257 with a primer on it but you cant so I want to buy a carb that is equivelent to the wt257.
I will see if I can make something to choke carb.
Thanks
I will see if I can make something to choke carb.
Thanks
08-25-2009, 06:43 PM
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RE: carbs
ORIGINAL: PEERPSI
The bulb clears the line of air and draws fuel up to the carb from the tank, for must people that is understood as primer bulb. Adding a primer bulb likely won't solve your problem. What might work is adding the 644 with choke. You could also keep what you have and use a plug on the carb intake while pull starting. Once it fires pull the plug out of the carb throat. Use a string or something similar to make it easy to pull out and hard to loose.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
The bulb clears the line of air and draws fuel up to the carb from the tank, for must people that is understood as primer bulb. Adding a primer bulb likely won't solve your problem. What might work is adding the 644 with choke. You could also keep what you have and use a plug on the carb intake while pull starting. Once it fires pull the plug out of the carb throat. Use a string or something similar to make it easy to pull out and hard to loose.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
Doesn't matter what they call the bulb, go read Walbro Service manual C-1022 for how this works.On a Walbro a Primer and Air purge are two different things.
The 644 has the same venturi size as the 257, but has a choke.
08-25-2009, 06:53 PM
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RE: carbs
Same bore dimensions as the 257 and 644 with an accelerator pump. Not likely to make it any easier to start. How close are the carb openings to the hull side? I know I read about someone having trouble with a similar hull because the carbs were too close to the hull. His problem was performance not starting though.
08-25-2009, 07:34 PM
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RE: carbs
ORIGINAL: Nosedragger
It does not put any fuel in the throttle bore, which is what is need for starting, to make starting easier you need to have fuel in the throttle bore, the choke on carbs so equipped do that by causing the vacuum from the intake port to draw fuel from the metering chamber into the bore and by restricing the air flow make a rich mixture that is easier to start then engine.
A non choke carb with a air purge bulb will be just as hard to start as a non choke non air purge bulb carb. You have to block the intake to carb to pull fuel from metering chamber or spin it fast enough for the air flow to create the pressue drop in the venturi needed to get fuel into the throttle bore.
Just use the 644 with the choke.
ORIGINAL: Dan S
The bulb is a primer,
yes it takes the air out of the line, but it primes the carb with fuel.
Dan.
The bulb is a primer,
yes it takes the air out of the line, but it primes the carb with fuel.
Dan.
It does not put any fuel in the throttle bore, which is what is need for starting, to make starting easier you need to have fuel in the throttle bore, the choke on carbs so equipped do that by causing the vacuum from the intake port to draw fuel from the metering chamber into the bore and by restricing the air flow make a rich mixture that is easier to start then engine.
A non choke carb with a air purge bulb will be just as hard to start as a non choke non air purge bulb carb. You have to block the intake to carb to pull fuel from metering chamber or spin it fast enough for the air flow to create the pressue drop in the venturi needed to get fuel into the throttle bore.
Just use the 644 with the choke.
your right, you still need the choke if using the bulb.
I knew that, don't know what the hell I was thinking, my bad.
Dan.
08-25-2009, 07:43 PM
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RE: carbs
ORIGINAL: wetsleeves
Hi,
I have two wt 257 carbs in my cat and I was wondering is there a carb with a primer bulb that would be the same.
I cant primer the carb by putting my finger over it as there is no room. I need two carbs with primers. I heard that the wt 644 are the same but with bulbs, is this true?
Also were would I be able to purchase them from?
Regards Peter
Hi,
I have two wt 257 carbs in my cat and I was wondering is there a carb with a primer bulb that would be the same.
I cant primer the carb by putting my finger over it as there is no room. I need two carbs with primers. I heard that the wt 644 are the same but with bulbs, is this true?
Also were would I be able to purchase them from?
Regards Peter
08-25-2009, 09:13 PM
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RE: carbs
ORIGINAL: Nosedragger
Doesn't matter what they call the bulb, go read Walbro Service manual C-1022 for how this works.On a Walbro a Primer and Air purge are two different things.
The 644 has the same venturi size as the 257, but has a choke.
ORIGINAL: PEERPSI
The bulb clears the line of air and draws fuel up to the carb from the tank, for must people that is understood as primer bulb. Adding a primer bulb likely won't solve your problem. What might work is adding the 644 with choke. You could also keep what you have and use a plug on the carb intake while pull starting. Once it fires pull the plug out of the carb throat. Use a string or something similar to make it easy to pull out and hard to loose.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
The bulb clears the line of air and draws fuel up to the carb from the tank, for must people that is understood as primer bulb. Adding a primer bulb likely won't solve your problem. What might work is adding the 644 with choke. You could also keep what you have and use a plug on the carb intake while pull starting. Once it fires pull the plug out of the carb throat. Use a string or something similar to make it easy to pull out and hard to loose.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
Doesn't matter what they call the bulb, go read Walbro Service manual C-1022 for how this works.On a Walbro a Primer and Air purge are two different things.
The 644 has the same venturi size as the 257, but has a choke.
My apologies to Nosedragger.
08-25-2009, 11:33 PM
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RE: carbs
Ok thanks for replies, I managed to sqeeze my finger over the carbs and started the motors, now one of the motors is idling fine but the other idles for around 5-10 secs then revs up and stalls. My understanding would be that its running lean until it starves for fuel and dies. Could someone tell me what is the standard settings for the low needle and if you screw the low needle in does that lean the engine or richen it up.
Thanks guys
Thanks guys
08-26-2009, 07:59 AM
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RE: carbs
ORIGINAL: PEERPSI
http://wem.walbro.com/distributors/s...viceManual.pdf Pages 27-28 of the PDF explains the difference between the primer and air purge systems. In Nosedraggers defence the WT manual calls the bulb a primer bulb but it is in fact a air purge bulb. None of the three carbs mentioned in this post, 257, 644 or 813 have primer systems. So bottom line is you need a way to choke the engines. The other option is to turn the jugs around so the carbs are inboard and exhaust out board.
My apologies to Nosedragger.
ORIGINAL: Nosedragger
Doesn't matter what they call the bulb, go read Walbro Service manual C-1022 for how this works.On a Walbro a Primer and Air purge are two different things.
The 644 has the same venturi size as the 257, but has a choke.
ORIGINAL: PEERPSI
The bulb clears the line of air and draws fuel up to the carb from the tank, for must people that is understood as primer bulb. Adding a primer bulb likely won't solve your problem. What might work is adding the 644 with choke. You could also keep what you have and use a plug on the carb intake while pull starting. Once it fires pull the plug out of the carb throat. Use a string or something similar to make it easy to pull out and hard to loose.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
The bulb clears the line of air and draws fuel up to the carb from the tank, for must people that is understood as primer bulb. Adding a primer bulb likely won't solve your problem. What might work is adding the 644 with choke. You could also keep what you have and use a plug on the carb intake while pull starting. Once it fires pull the plug out of the carb throat. Use a string or something similar to make it easy to pull out and hard to loose.
I had a 644 and went to a 257. Once you learn to listen for the pop when the throttle is plugged, I use my thumb, it's just as easy to start even with out the prime bulb.
Just for you Nosedragger http://wem.walbro.com/distributors/s...s/WTseries.pdf item 62.
Doesn't matter what they call the bulb, go read Walbro Service manual C-1022 for how this works.On a Walbro a Primer and Air purge are two different things.
The 644 has the same venturi size as the 257, but has a choke.
My apologies to Nosedragger.
No apology needed, Walbro created the confusion with the terminology they use.A lot of people have trouble their starting
engines because of this,once they understand how it works most of the starting problems go away. I don't wrench on these for a living but work on a couple dozen a year.
08-26-2009, 08:21 AM
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RE: carbs
why not make a gadget that you can use instead of your finger. Maybe a rubber stopper on the end of a metal probe of sorts. Like the probe mirrors that dentists use to check your teeth but with a rubber bung where the mirror is. Might work.
08-27-2009, 04:54 AM
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RE: carbs
wetsleeves...
Carby packadged and will send off in the post tommorow. Hope it helps you outta ur problem...Half of it any way..lol
Cheers Scoot
Carby packadged and will send off in the post tommorow. Hope it helps you outta ur problem...Half of it any way..lol
Cheers Scoot
08-28-2009, 12:03 AM
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RE: carbs
ORIGINAL: wetsleeves
the only way I can start the motors is by pulling the plugs out and adding fuel through the plug hole. Its a real pain so i want a carb that is equivelent to the wt257 but with a primer bulb.
Also is there some were on line I could order them from?
the only way I can start the motors is by pulling the plugs out and adding fuel through the plug hole. Its a real pain so i want a carb that is equivelent to the wt257 but with a primer bulb.
Also is there some were on line I could order them from?
O'neill brothers racing is the best place to get.
PS,
GREAT trick is too take the discharge fuel once purge primer is recycling and inject it down the carbs throat.
One or two pumps on bulb once fuel is discharging will fire up engines in one or two pulls
Pictures show this type direct priming done within an intake snorkle, but very easy to fabricate a tube ( WD40 can ) into a simple bracket doing the same thing
