Drilling out an adjustment screw plug

[Guest]

Tearing down my carbs for a cleaning dip and I've run into this problem: There is a plug (I assume this is what it is based on the pictures provided by Flaming Chainsaws' tutorial) that needs drilled out.

1. Recommendations on the best way to do this? Anyway I can remove this plug without drilling?

2. Why is this plug here? Will I need to replace it when done?

3. I assume dipping the carb body with this in place is a bad idea due to the o-ring on the adjustment screw. Am I correct?

Thanks for your help!

Jeremy

[tkent02]

Just take a 1/8 or so bit, twist it in gently until it gets stuck, pull sideways to pry the plug off. You don't need to replace it. Pretty easy.

[Big T]

Use a tack or small nail and tap it into the center

It should deform the plug enough so you can pry it out

[Redman]

1) Either of the above.
You dont really want to "drill it out".
More like you want to find a way to "pull it out" or "pry it out".

2) Why is it there? So manufacture could claim it was not a user adjustment.

3) Yes, you want to remove the plug so can remeve the adjustment needle and its o ring.
No real need to replace it.


.

[BassCliff]

Hi,

Have a look see....

GS450 Carb Rebuild Guide
(Mr. Flaming Chainsaws)

Starting on page 13 of the guide below you will find instructions for removing the idle mixture screw (pilot screw) cap...

Mikuni BS(CV) Carburetor Rebuild Tutorial
(Mr. Nessism)


Thank you for your indulgence,

BassCliff

[Bonehead]

I actually drilled them out as per the carb rebuilt .pdf on Cliff's website. Was very easy, but I understand how easy it would be to screw up the brass underneath. Just not the depth of whatever you get in there so you do not deform the screw below.

[Steve]

The aluminum plug is about 2-3 mm thick, then there is a bit of a gap, about 3-4 mm, then the mixture screw. Use a modest drill bit (the sharper, the better) at a slow speed, it will tend to 'bite' because of the slow speed, just let it stop the drill, then lever the plug out of place.

No need to put them back, you may want to adjust your mixture from time to time.

They were there because the EPA dictated cleaner-burning bikes, so the carbs were pre-set at the factory, then sealed. For several years, it was illegal to remove them and make adjustments.

.

[twodogs58]

Left hand

drill bits will often bring them out used gently and reduce the risk of driving the adjustment screw in.

[tkent02]

For several years, it was illegal to remove them and make adjustments.

.

I bet it still is illegal.

[yank]

The aluminum plug is about 2-3 mm thick, then there is a bit of a gap, about 3-4 mm, then the mixture screw. Use a modest drill bit (the sharper, the better) at a slow speed, it will tend to 'bite' because of the slow speed, just let it stop the drill, then lever the plug out of place.

No need to put them back, you may want to adjust your mixture from time to time.

They were there because the EPA dictated cleaner-burning bikes, so the carbs were pre-set at the factory, then sealed. For several years, it was illegal to remove them and make adjustments.

.

Thanks Steve: Now I can add that to my list of laws I broke!!!(LOL)

[limeex2]

carefully drill the plug as suggested here. Grind the sharp tip off of a wood screw. Screw it in, pull screw/plug with claw hammer. At the dealership, we did so many carb jobs, the tech's had a wood screw brazed to a dent puller for this purpose.