Author Topic: Any tips on removing stubborn brass drain screws on float bowls?  (Read 256 times)

Offline AshimotoK0

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Any tips on removing stubborn brass drain screws on float bowls?
« on: February 20, 2020, 07:40:00 AM »
As title .. any tips on removong without shearing off  ?
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Offline kevski

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #1 on: February 20, 2020, 08:18:18 AM »
soak in diesel for a couple of days, then use one of those battery screwdrivers that are similar to a rattle gun, just done a bank of carbs for a KZ1000 that had been submerged in what looked like mud for a number of years.

Offline Bryanj

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #2 on: February 20, 2020, 08:18:45 AM »
Nope, sheared a few! Maybe heat?

Offline AshimotoK0

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #3 on: February 20, 2020, 08:29:42 AM »
Trigg  suggests local heat concetrated on the brass drain screw. Anyone know the thread size ... I guess M6 x 0.75 mm pitch

Will also try the diesel soak Kev

Update ... Hoping it is M6 x 0.75 as just found these I didn't realize I had !  :)

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« Last Edit: February 20, 2020, 08:46:39 AM by AshimotoK0 »
“Alright friends, you have seen the heavy groups, now you will see morning maniac music. Believe me, yeah. It’s a new dawn.” Grace Slick, Woodstock '69 .. In the year of the Sandcast.

Offline bobv7

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #4 on: February 20, 2020, 08:58:37 AM »
Just done 2 of these. Clamped the bowls in the Workmate, heated them with a gas torch for a few seconds but kept the flame moving. Used the largest screwdrive I've got and eventually they came free but needed replacing because the slots are soft, shallow and easily damaged.

Offline Tomb

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #5 on: February 20, 2020, 09:12:50 AM »
I used a gas soldering iron as a blow torch, the best thing for carbs as the heat can be used VERY locally on what you're trying to remove without risk of damage to the aluminium parts.
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Offline kevski

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #6 on: February 20, 2020, 08:18:46 PM »
That's the size of the threads on the thou's bowls, i even made new bowl screws out of brass, heads 5mm thick and a 2mm slot 3mm deep, these won't stay locked in.
« Last Edit: February 21, 2020, 08:25:32 AM by kevski »

Online mike the bike

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #7 on: February 20, 2020, 10:22:48 PM »
As above with the heat, diesel etc, before trying to loosen them, see if they'll tighten up slightly first - just to crack the seal.
Usually the tightening side of the slot is in better nick than the loosening side and the screwdriver will have a better purchase.
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Offline Moorey

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #8 on: February 20, 2020, 10:49:34 PM »
If you don't have a large hollow ground screwdriver use a piece of flat plate steel as near the thickness of the screw slot width as you can. It's far less likely to cam out of the slot and is easier to turn. Fasten bowls in a vice and heat the screw.  ;)

Offline ka-ja

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #9 on: February 21, 2020, 09:44:32 AM »
Plenty of heat and them douse with cold water, trying to leave the bowls hot.
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Offline MrDavo

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Re: Any tips on removing stubborn brass drain screws on float bowls?
« Reply #10 on: February 21, 2020, 12:11:43 PM »
I had this problem with my CL450 - although the carbs were in good condition, those soft drain screws hadn't been out for decades, as the old fuel in the bowls dried into a nasty grey powder. They were well and truly stuck.

In desperation I put them in the vice (using rags to protect the alloy and being very careful only to wind the vice in enough to locate, not crush them!), and got the blowlamp out, and heated them up, the alloy should expand more than the screw. It was hard to get enough purchase on the slightly damaged screw slots, so I used a large cranked screwdriver , like this:



That way I got lots of torque on the screw, once the bowl was good and hot, both screws suddenly came free with a crack.

Edited to add: A similar procedure, but using a fine cranked screwdriver and heat, was also needed to get out the brass jets, which were also stuck in the carb body with corrosion and powdered dried out fuel, as well as blocked with the same crud.

Spurred on by my success I then used the blowlamp to heat the carb body while I drifted out the stuck brass float pins with a fine drill, all fun and games until the solder holding the brass float assembly together melted and, to my horror, it all fell apart in an instant....  :-[ :-[ :-[
« Last Edit: February 21, 2020, 12:14:46 PM by MrDavo »
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