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rebuilding carbs
exvalvesetdabbler:
I decided to have a go making the drain screws and had a practice run this morning. Here's what came out of the garage.
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The OEM screw is the tarnished one with screwdriver marks in the slot.
A little refining of methodology and it should be doable. The first mistake was in cutting the screws slot and then facing off the screw. It caused the tool to jump a bit. Second was removing one thread too many closest to the screw head.
The 1 mm drill bit was a bit blunt after using it on fibre glass PCB material so I picked up a couple of new ones this morning.
Regards
Dave
Johnny4428:
That looks just great Dave! Have you tried it in the carb float bowl?
exvalvesetdabbler:
--- Quote from: Johnny4428 on May 13, 2026, 12:50:11 PM ---That looks just great Dave! Have you tried it in the carb float bowl?
--- End quote ---
Short answer - doesn't fit
Long answer - the old knackered carbon steel die I found lying around is giving me an oversized thread.
This was a run through to make sure I had the necessary tooling and holders. I'm sure with a decent die and a regrind of the lathe tool to give a smoother finish on the underside of the screw head it will be ok.
Regards
Dave
K2-K6:
Nice aesthetic in that though, which will make a good replacement when small issues, mentioned above, are resolved.
Does anyone else find that you need a unusually large flat blade screwdriver to engage them properly, and not just twist them in middle of slot that leads to "camming" out along with that subsequent mushing of the slot ?
Also need one with very good condition "grind" and flat end to let it engage fully and deep into slot.
exvalvesetdabbler:
I have a big flat blade screwdriver intended for electricians that usually gives a snug fit. The trick is not to overtighten them in the first place.
But you're right if some monkey uses a too small too thin driver the slots get chewed.
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