Briggs air cleaner screw

[creia]

Briggs part # 93322
This is the screw that holds the air cleaner lid on the old Briggs Flatheads. Does anybody know what the thread is? I have a carb that the receiving threaded boss is bunged and I'd like to try re tapping it.
Thank you,
Michael

[bgsengine]

it can vary but usually 10-32 or 12-24.. you can check if you have small size machine screw kit and see which nut threads on to the screw.

[Arkie]

The vert shaft Briggs flatheads are 10-32.

The larger HP briggs that use the larger old flo jet carbs may be a larger size thread.

I have a Klein electrical wire stripper/crimper tool #1010 that I can grab from work bench pegboard and do a fast machine screw thread check and also use it to cut to length BRASS machine screws. I do not use it for cutting steel screw to length.
You can find some cheaper machine screw thread checkers.
I have all kinds thread checkersm machine screw taps and dies and a large assortment of small machine screws, it's just more user friendly and faster using the Klein sometimes.
Here is a link to view the Klein.
https://www.amazon.com/Klein-Tools-1010 ... B0000302WX

Good luck with the re-tap of the aluminum briggs carb for the screw/bolt.
I've had to tap to a larger size thread on some of those types and use a stud or splice the 10-32 Briggs steel screw with a larger size thread.
Once you have piddled around with re-tapping and just re-doing/re-working a measley breather hold down bolt you will be more careful using fingers only and not force or cross thread the fine threaded breather screw into future aluminum pot metal NLA carbs and also stop tightening when it gets somewhat secure. Disgusting also when you find that someone else has already stripped one.

[creia]

Thank you gentlemen- very much appreciated!
I am hoping that the re tapping will work. This is a restoration of a 1965 Briggs 3 HP horizontal shaft with the original carb so it needs to have the OEM Briggs look with the original screw retaining the air filter lid. (Arkie- Yes it was buggered by the previous owner and I share your feelings 100%.
Michael

[Skywatcher]

Hi Creia

Contact your local auto supply store (NAPA, Auto-Zone etc.) and see if they can get a 10-32 Heli-Coil or similar thread insert kit. It may cost a few dollars, but you'd be keeping your vintage engine as close to original as possible. Inserting the threading tap true and square will be essential for a proper repair. I believe I read somewhere on this forum a while ago that 91% isopropyl alcohol is the best cutting fluid for aluminum and pot metal. All the best,

Sky

[KE4AVB]

That is what I use now after being recommended by my machinist that does a lot of my machine work. The taps dont seem to jam up cutting threads as they did using oil (Tap Magic).

[bgsengine]

yes to the 10-32 helicoil kit ( I used them quite a bit) However - Use *EXTREME* care when tapping those delicate standoffs in the carb - try and make sure they go in very smoothly (and even better, carefully drill out old threads with a *SHARP* correct size drill bit for the helicoil kit) - they (Carb casting) crack and split very very easily trying to drill or tap them, so a steady hand and tons of patience are needed with those.. ask me how I know.. hehehe

I probably screwed up a half dozen carburetors over the years just getting careless trying to put in a heli-coil but have had good success rate at it. In some cases if they do crack or split, it is also possible to re-form the broken off pieces with a bit of modern epoxy..(never done it yet myself but have seen at least one with such a repair, evidently done at a professional machine shop..or maybe just someone really good.. or lucky.. at it.. )

[creia]

Thank you ALL for the continued interest and help.
Brian (bgsengine)- Understood, duly noted, and (especially) appreciated!
I will report back with my results...
Michael

[Arkie]

I sometimes make a sleeve over a cast post before I attempt tapping so as to secure the side from cracking before threading.
I've used copper pipe or take a hex nut and drill to size and slip over the cast post.
I also have used regular bar soap as a tap lube when tapping aluminum.

[Arkie]

I sometimes make a sleeve over a cast post before I attempt tapping so as to secure the side from cracking before threading.
I've used copper pipe or take a hex nut and drill to size and slip over the cast post.
I also have used regular bar soap as a tap lube when tapping aluminum.