Briggs "Pulsa-Jet" carb fuel pipe replacement

[creia]

I picked up a brand new genuine BRIGGS OEM/NOS 5 HP "Pulsa Jet" carb for next to nothing. Only one problem....
The shorter nylon fuel pick up tube (Briggs part # 296811/497413) is missing. This is the tube that pulls fuel from the tank reservoir cup up into the carb.
It looks like there WAS one installed (remnants of some kind of sealant/adhesive in the hole in the carb) at one time and was removed for some reason.
Here's my questions:
1. Is a new install just a press fit into the carb body? On every Briggs Pulsa Jet carb I have ever seen there looks like some kind of black-colored sealant or adhesive (epoxy?) surrounding the tube that enters the carb body.
2. What type of sealant/adhesive is used for this? (Must be fuel-proof, not just fuel resistant)
3. Looks like I need to remove any/all prior adhesive residue before installing the new one to get a proper fit? (I have a NOS fuel pipe one in inventory)
The Briggs repair manual is confusing in this regard as it states in the manual that you remove the old one and install the new one (righty tighty/lefty loosey) using a socket wrench, however, I see no evidence of any threads on either the end of the fuel pipe or inside the carb body hole?
Does anybody have any experience replacing these? I would really like to be able to use this carb for one of my rebuilds.
Thank you all,
Michael

[bgsengine]

I picked up a brand new genuine BRIGGS OEM/NOS 5 HP "Pulsa Jet" carb for next to nothing. Only one problem....
The shorter nylon fuel pick up tube (Briggs part # 296811/497413) is missing. This is the tube that pulls fuel from the tank reservoir cup up into the carb.
It looks like there WAS one installed (remnants of some kind of sealant/adhesive in the hole in the carb) at one time and was removed for some reason.
Here's my questions:
1. Is a new install just a press fit into the carb body? On every Briggs Pulsa Jet carb I have ever seen there looks like some kind of black-colored sealant or adhesive (epoxy?) surrounding the tube that enters the carb body.
2. What type of sealant/adhesive is used for this? (Must be fuel-proof, not just fuel resistant)
3. Looks like I need to remove any/all prior adhesive residue before installing the new one to get a proper fit? (I have a NOS fuel pipe one in inventory)
The Briggs repair manual is confusing in this regard as it states in the manual that you remove the old one and install the new one (righty tighty/lefty loosey) using a socket wrench, however, I see no evidence of any threads on either the end of the fuel pipe or inside the carb body hole?
Does anybody have any experience replacing these? I would really like to be able to use this carb for one of my rebuilds.
Thank you all,
Michael

Plastic (Nylon) Tubes: these are threaded in (when they enter carb body directly) , you will note the hexagonal shape of the pickup screen? The black adhesive is just a sealant they used (hardening sealant sorta like a glue, I guess, whereas most stuff woulda been labelled "Non-Hardening") For sealant you could pretty much use a little dab of just about anything compatible with metal to plastic bonding that isn't going to melt the nylon tube. (a tiny dab of thick CA glue perhaps) then the tubes are threaded in (you'll want to make sure the body threads are clean and not nicked or cracked) As the threads are sorta "rolled" it isn't possible to chase threads or re-cut them.... Nylon tubes don't have threads, carb body threads are rolled/formed and not very pronounced (you'd need an otoscope to get a good look at em) and often on used carbs those threads can be corroded away to little more than barely-detectable bumps...

As you know plastic tubes that connect to brass tubes are a slip-fit .. Brass tubes into aluminum body are VERY press-fit (as in hot carb body and cold bronze tube press fit under precision hydraulics) so are very very difficult to remove & replace.

Edit to Add: Forgot to mention CA glue = Cyanoacrylate .. A.K.A. Super Glue (But you DO have to work quickly on clean and VERY DRY moisture-free parts - CA glue cures quickly near water, possibly before you can get tube fully inserted... and almost instantly if you drop baking soda or other acid neutralizer on it)

[creia]

Thank you Brian!
I looked again (with a good light and a magnifying glass) and I can just barely see some threads in the carb body- VERY subtle. The problem is that much of the threads are covered and hidden by residual sealant/adhesive, which I am sure I need to remove for proper fitament. Got any tricks on how that is done? I did try picking at it but it is really on there. I am concerned that if I go at it too aggressively I'll also destroy the tiny threads in the process. Do you think that a good hot ultrasonic treatment would loosen it up for easier removal? Do I understand correctly that this is a "sealant" (to stop air leaks that would effect the fuel pumping action) and not an "adhesive" (to secure the nylon tube)?
Michael

[38racing]

Thank you Brian!
I looked again (with a good light and a magnifying glass) and I can just barely see some threads in the carb body- VERY subtle. The problem is that much of the threads are covered and hidden by residual sealant/adhesive, which I am sure I need to remove for proper fitament. Got any tricks on how that is done? I did try picking at it but it is really on there. I am concerned that if I go at it too aggressively I'll also destroy the tiny threads in the process. Do you think that a good hot ultrasonic treatment would loosen it up for easier removal? Do I understand correctly that this is a "sealant" (to stop air leaks that would effect the fuel pumping action) and not an "adhesive" (to secure the nylon tube)?
Michael

Maybe soak with stinky paint thinner/remover unless that might affect aluminum too.

[bgsengine]

Thank you Brian!
I looked again (with a good light and a magnifying glass) and I can just barely see some threads in the carb body- VERY subtle. The problem is that much of the threads are covered and hidden by residual sealant/adhesive, which I am sure I need to remove for proper fitament. Got any tricks on how that is done? I did try picking at it but it is really on there. I am concerned that if I go at it too aggressively I'll also destroy the tiny threads in the process. Do you think that a good hot ultrasonic treatment would loosen it up for easier removal? Do I understand correctly that this is a "sealant" (to stop air leaks that would effect the fuel pumping action) and not an "adhesive" (to secure the nylon tube)?
Michael

I never concerned myself too much with the leftover sealant - didn't bother trying to pick off small bits of goo that stuck hard to the metal.. cleaned off whatever was easily accessed , throw in new tube & sealant and good to go. - The nylon does have a bit of squish as you thread it in, so leftover sealant IN the threaded area is not a problem (remember, it wouldn't be there if it didn't have space to squeeze between old tube and carb, right?)