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]

That looks just great Dave! Have you tried it in the carb float bowl?

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.

[Oddjob]

Were you aware that there is a Honda special tool for the clutch adjuster on the 500-4 Nige. The big slotted thing in the drive chain cover. Might also fit the drain screws, never tried it but seem to recall it’s a multi bladed tool

[K2-K6]

Were you aware that there is a Honda special tool for the clutch adjuster on the 500-4 Nige. The big slotted thing in the drive chain cover. Might also fit the drain screws, never tried it but seem to recall it’s a multi bladed tool

I was much more involved with the 750s Ken, and so not familiar with that tool. Sounds like it could be good for this though.

My own method is a great big woodworking screwdriver that my dad used to drive in big brass hinge screws by hand (before electric tools were invented    )not sure, but either Stanley or Marple brand, the type with see through yellow resin handles for properly leaning into the job in door hanging.