old briggs engine, carb inquiry

[sgull]

I see. Thanks again bsgengine for another of your helpful replies.

[Deere2me]

Reason for checking at the fuel bowl vent boss - further in near the venturi you may spy another small hole - That is your idle fuel passage that feeds fuel up to the idle mixture needle... if that leaks air, you got problems -

That ain't right! The idle mixture screw/port is fed from the emulsion tube.


BTW sgull, don't you have a MANUAL that would explain most of the carb workings???

edit/add:
You need to sit down and study what materials have been made avail. to you, no?


Eight pages on such a simple subject. I'll bet that's more than any other post has garnered in over six months...sheesh!

[sgull]

sgull, don't you have a MANUAL that would explain most of the carb workings?

Regarding a MANUAL, I am doing what I can do with the "Repairman's Manual 1918 - 1981" as linked at the bottom of the list in the first post here: viewtopic.php?f=6&t=1014
In addition, I am consulting these guidelines/instructions for the carb: http://outdoorpowerinfo.com/repairs/bri ... _piece.asp

It seems the info regarding the carb as included within that Repairman's Manual describes cleaning, disassembly, reassembly, adjustments/checks and such, but I wouldn't say it particularly actually "explains the carb workings" to much of an extent, although to some degree I suppose.

[bgsengine]

Reason for checking at the fuel bowl vent boss - further in near the venturi you may spy another small hole - That is your idle fuel passage that feeds fuel up to the idle mixture needle... if that leaks air, you got problems -

That ain't right! The idle mixture screw/port is fed from the emulsion tube.

Correct - I was actually thinking of the ones with removable venturi and that port is the air bleed to the emulsion tube. they have a separate gasket for the venturi. the large 2-piecce does not have such a air bleed in that area.
The .002 warp limit is more to do with the sealing surfaces of the carb venturi/throat. Unmetered fuel leaking into intake and all that.. In any case, it SHOULD be flat and surfaces should mate cleanly all around for best results.

edit/add:
You need to sit down and study what materials have been made avail. to you, no?

and he evidently has

Eight pages on such a simple subject. I'll bet that's more than any other post has garnered in over six months...sheesh!

And, what's wrong with that? just because YOU know everything does not mean that someone inexperienced in the field should not be asking questions as to the how and why of things. Note one of the key words in the forum name: *EDUCATION*

[Deere2me]

Reason for checking at the fuel bowl vent boss - further in near the venturi you may spy another small hole - That is your idle fuel passage that feeds fuel up to the idle mixture needle... if that leaks air, you got problems -

That ain't right! The idle mixture screw/port is fed from the emulsion tube.

Correct - I was actually thinking of the ones with removable venturi and that port is the air bleed to the emulsion tube. they have a separate gasket for the venturi. the large 2-piecce does not have such a air bleed in that area.
The .002 warp limit is more to do with the sealing surfaces of the carb venturi/throat. Unmetered fuel leaking into intake and all that.. In any case, it SHOULD be flat and surfaces should mate cleanly all around for best results.

edit/add:
You need to sit down and study what materials have been made avail. to you, no?

and he evidently has

Eight pages on such a simple subject. I'll bet that's more than any other post has garnered in over six months...sheesh!

And, what's wrong with that? just because YOU know everything does not mean that someone inexperienced in the field should not be asking questions as to the how and why of things. Note one of the key words in the forum name: *EDUCATION*

Dang! You're like the third person to say that on here! 'Preciate it!

[sgull]

I'm considering plugging off the filter drain at the bottom of the carb (plugging it with a welch plug or perhaps sealing it with a bolt and nut has been suggested) if I can't obtain a replacement filter for it and the little tang part that holds that filter in as well (the little tang is missing because I lost it, and the old filter was deteriorated). My understanding so far is that the purpose of the drain there is to drain any moisture or excess fuel that can collect in the air intake and get sucked in on the next start ups, and that the little filter installed there prevents sucking in dirty air from past the main filter. My concern about plugging off that drain would of course be the defeating of the purpose of having the drain there in the first place. So in that case wouldn't plugging that drain be an ill-advised approach if I cannot obtain the proper little filter replacement and tang/holder part, or if I did plug the drain as described what would/should I need to do otherwise about that moisture or excess fuel which potentially will collect there?

Here's a photo; the hole for that filter/drain is the one to the right:

[bgsengine]

I'm considering plugging off the filter drain at the bottom of the carb (plugging it with a welch plug or perhaps sealing it with a bolt and nut has been suggested) if I can't obtain a replacement filter for it and the little tang part that holds that filter in as well (the little tang is missing because I lost it, and the old filter was deteriorated). My understanding so far is that the purpose of the drain there is to drain any moisture or excess fuel that can collect in the air intake and get sucked in on the next start ups, and that the little filter installed there prevents sucking in dirty air from past the main filter. My concern about plugging off that drain would of course be the defeating of the purpose of having the drain there in the first place. So in that case wouldn't plugging that drain be an ill-advised approach if I cannot obtain the proper little filter replacement and tang/holder part, or if I did plug the drain as described what would/should I need to do otherwise about that moisture or excess fuel which potentially will collect there?

Filter is part number 27590 (about 3 bucks) and the retainer is part number 211954 (No Longer Available) - but with luck you might find one on ebay or a bing search - Alternatively look for any 8-10 HP one piece flo-jet carburetor body (even a junked one) -with a newer design - they had a sort of brass mesh plug/filter - it would drain liquids while still filtering air. They were put in place and staked in, you might be able to rescue one out of an old junked carb body (destroying the carb body in the process) and fit it up to yours like a welch plug and stake it in place. You won't find them as service parts, I do not believe.. they were not supposed to come out... and I've yet to find a parts catalog that shows them being serviceable.

Alternatively you might be able to fabricate something if you can find a similar 'plug filter' (Things like oil filler plug vents on some air compressors, gearboxes, etc. come to mind) and machine it down to fit.

(to illustrate - the top middle in this pic shows an example of what I mean.)