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Carburetor question


MrSteele

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During the BGB rebuild/engine rebuild current project, I decided stupidly to rebuild a carb that was giving few problems before taking it down for the other work, thought a new needle would solve the problem. Would have, too, had it not been for the emulsion tube that would not budge. I finally backed it out far enough to get the top off, but made a heck of a mess out of the screwdriver groove. Has anyone ever revised a later model flo-jet to accommodate the older engine? My valve cover is not the crankcase breather. My carb is the one pictured without the cast in air cleaner neck. I have several other carburetors, but they all have the cast neck. I am wondering if anyone has modified the later model with a cast neck by removing the neck and using the steel air cleaner neck in its place. Pics are attached. I am thinking I can cut the later model carb at the blue line to accommodate the older style. Any discussion will be appreciated. I do have several 23D carbs/air cleaners that could also be used with no modifications

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5c72fd458d072_10hpcarb.thumb.jpg.05e07b98da46768aa173b8037885694f.jpg

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I have seen two options performed.

First option was to have the hole patched & welded by an experienced welder as the casting isn't the greatest.  You're option of removing the section of neck sounds like a better option.

Second is to locate the valve cover with the breather tube hole & add the second breather tube or remove the old breather & pipe plug the hole.

Depending on how bad your threads are in the emulsion tube hole, the thread pitch is 5/16"x32.  Briggs makes a tap set that has the 5/16"x32 & the 1/4"x32 plug taps for straightening these out following a difficult removal as you are experiencing.

Edited by ShaunE
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@ShaunE I'm thinking that the early style breather attaches with a single bolt in the center and thus the crankcase does not have the ears and threads to attach the newer style breather. 

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2 minutes ago, Chris727 said:

@ShaunE I'm thinking that the early style breather attaches with a single bolt in the center and thus the crankcase does not have the ears and threads to attach the newer style breather. 

That's a good point.  I have nothing here new style to look at.

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I had a third option.

 Find a later model filter plate and cover, then wrap the cast in air cleaner neck with high end duct tape. The real aluminium kind. It's o the air side, so fuel compatibilty isn't needed.

My 23D ran like that for years, and would still be that way today if I were using it regularly.  I know it's not right, but it worked.

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19 hours ago, ShaunE said:

I'm thinking that the early style breather attaches with a single bolt in the center and thus the crankcase does not have the ears and threads to attach the newer style breather. 

The newer style is the one I am considering cutting the neck off of. The top of the neck has a plate that rests on the outside, that the top cover of the air cleaner would sit on, then the bolt through the center would attach just as it did in the older one. I say this is a newer style, but there are newer, I suppose. I thought about a valve cover, might even have a couple laying around, but I believe the plate is wider than the valve cover. Will have to reconsider and look to be certain. Something is going to happen. I do not have an engine for the newer style carbs that I have. I buy the old flo-jets when I can find them, is why I have a couple laying around the shop most of the time.

 

5 hours ago, GWGAllisfan said:

My 23D ran like that for years, and would still be that way today if I were using it regularly.  I know it's not right, but it worked.

I have 3 23D engines and 2 carburetors for them, even thought about using one of them on this engine

19 hours ago, ShaunE said:

Depending on how bad your threads are in the emulsion tube hole, the thread pitch is 5/16"x32.  Briggs makes a tap set that has the 5/16"x32 & the 1/4"x32 plug taps for straightening these out following a difficult removal as you are experiencing.

5 hours ago, GWGAllisfan said:

 

Well, it would seem that I am not the first to take this one apart? and it would also seem that the others working on it had never heard of a screwdriver that fits the tube, but is narrow enough at the blade to not cut the casting out when removing the tube. I have had trouble keeping the carb adjusted, and know why, now. There is not enough thread stock left to hold the screw, a tap will likely fall completely into the hole without touching the sides. If I could get the tube out, I would consider using something like Belzona or a Helicoil to repair threads. I have some 5/16-32 short and long helicoils left over from a similar repair on a Model 9 Briggs carburetor. I was just trying to think of an easier way out. There is less stock on this carb than it was on the Model 9 carburetor. I used a Loctite Form a Thread on an old 2 cycle Jacobsen carb a few years ago. https://www.napaonline.com/en/p/NCB28654. It worked fairly well. I would get a unit of Belzona like we used to repair stripped bolts at a plant I worked in a few years ago, but minimum order is a bit pricey. If I could find someone in the plant that could make a small purchase from the warehouse.....

Something is going to happen this week, going to try the tube removal again. Thanks!

I am likely a little different than most, I want the engines and their parts restored, the lawnmower is just a place to showcase the engine, and the Simplicity machine is a fine showcase!

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3 hours ago, MrSteele said:

and it would also seem that the others working on it had never heard of a screwdriver that fits the tube, but is narrow enough at the blade to not cut the casting out when removing the tube.

Bingo!

I have a Klein that fits perfectly with no modification.  The only thing it gets used on is emulsion tubes & jets.  And my 5/16"x32 Die has saved enough emission tubes from the recycling bin that it has paid for itself.

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My biggest problem is that the end of the emulsion tube will not hold a screwdriver of any sort, it is eaten out, or, the ears that would hold a screwdriver blade are rounded. I can back it out far enough to remove the top, then it will not go further. At a later date, I intend to drill and collapse the tube from the inside, install  a couple Helicoils, or one long one if it is enough, then try again. I cut the carb as I originally considered, but the tube on the old air cleaner is too small to seal in the opening. A trip to Hobby Lobby might yield a piece of plastic sheet around .017 thick to make a permanent shim for the tube. If not, duct tape around the tube, slip into place, and trim so it is not noticeable, then tighten carefully to prohibit air leaks. Will keep you posted, with pics when I find the entire solution

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  • 1 month later...

Update. I have finished the carb manipulation with a pretty chrome extension. I did cut the section of the later model carb off. The air cleaner extended too far into the hole, and would not seal of fit at all. So, I tried bushing the different length by heating a piece of PVC and shoving it into the carb. Did not work. Shopping trip! a chrome, 11/2" tailpiece fit the air cleaner original extension, barely. I cut it off, made a few changes, and now have a pretty piece of chrome on my carburetor! See images below. The sealer I used is Red-Kote gas tank sealer. It is gasoline proof, so should not be bothered by gas, spilled, backfired, flooded or? I intend to add a good bead of 3M Yellow weatherstrip adhesive as a sealer at the joint between the extension and the air cleaner stem. Silicone is the last idea for anything in my shop, only using it where specified, such as in Kohler valve cover gaskets

Carb1.thumb.jpg.d2a720a95070b0dc89f92044a54b56f6.jpgCarb2.thumb.jpg.897f34d60d5055c8da5c50b1141daecb.jpg5ca63668a8448_Carbmod.thumb.jpg.9e3254073b754e9c0700ffdee037a973.jpg5ca6366b603dd_Carbmodsealant.thumb.jpg.13a1e6949c2e2f081c5fa789f8a84b50.jpg5ca6366041714_CompletedCarb.thumb.jpg.2c1e8267f4654ec0fdeb060ea027e4d2.jpg






 

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