Topic: Snapped off Carb Drain Screws

[BenelliSEI]

Clearing through more bits that came with the Chopper/K0 purchase. Four very nicely polished float bowls. Two already had the heads snapped off the drain screws (later style, with the larger head). In the usual fashion, I turned the third one with the same immediate result! Tried some heat/cooling and penetrating oil on the last one and it just came from even more easily (snapped off, just like the others).

All four now have the shank firmly in place. Any clever suggestions?

[Don R]

 Wow. I considered turning a set of replacement screws down to match the early ones but I found the missing early one and didn't need to. I think I got them from 4into1 . One of my racing friends suggested a torx bit instead of an easy out. He claims to have had better luck. I've used the left hand bit with the cone shape easy out with good results.
https://caseclear.us/products/screw-extractor4-pcs-5pcs-6pcs-2?variant=39728556081320&utm_medium=cpc&utm_source=bing&utm_campaign=Bing%20Shopping&msclkid=d8d8461096981c2166a526b4b8fe9aeb

[Gamma]

Yes I suppose it’s now down to careful drilling and using the right type of easy-out with some heat. They are buggers when they are stuck, I just tried to replace some on my Suzuki as screw slots were worn, but I couldn’t undo them, so stopped before I sheared them off😀
I’ve used various eazy-out types over the years, and also the tang of a file, the tang will twist before it breaks, nothing worse than an easy-out shearing flush

[BenelliSEI]

Yes I suppose it’s now down to careful drilling and using the right type of easy-out with some heat. They are buggers when they are stuck, I just tried to replace some on my Suzuki as screw slots were worn, but I couldn’t undo them, so stopped before I sheared them off😀
I’ve used various eazy-out types over the years, and also the tang of a file, the tang will twist before it breaks, nothing worse than an easy-out shearing flush

All good ideas..... I lik the file tang. Nothing worse than having a broken easyout in the hole......
I think I hav a few left hand drill bits left. I don’t need these for anything right now, because t the bowls are all useless the way they are now!

[Doobie]

I've never been successful in getting a busted piece out using every kind of tool you can think of without mangling the threads. The first thing I try now is to heat the area well using a mini torch - it works maybe half the time.

[BenelliSEI]

I've never been successful in getting a busted piece out using every kind of tool you can think of without mangling the threads. The first thing I try now is to heat the area well using a mini torch - it works maybe half the time.

That’s what I did with the last one, and ended up with a matching set! Fortunately I don’t need these for any specific project, but they are beautifully polished. Worse outcome will be they get trashed in frustration.

[Kevnz]

Not sure if it's applicable in this case, but I had a valve cover where the tappet covers were well and truly seized in place. Levering on them was either going to round off the head or snap the cover (it was in a vice). Put it in the gas bbq at 200C for about 15 min. All tappet covers came out with a minimum of resistance. With brass and aluminium, I expect the expansion rates will be different to alloy\alloy, but that may or may not be a good thing. Either way, a few heat cycles ( heat\cool, heat\cool may assist in breaking the seal. Obviously you will still need to use the previously mentioned techniques as well, but it may help.

[BenelliSEI]

Not sure if it's applicable in this case, but I had a valve cover where the tappet covers were well and truly seized in place. Levering on them was either going to round off the head or snap the cover (it was in a vice). Put it in the gas bbq at 200C for about 15 min. All tappet covers came out with a minimum of resistance. With brass and aluminium, I expect the expansion rates will be different to alloy\alloy, but that may or may not be a good thing. Either way, a few heat cycles ( heat\cool, heat\cool may assist in breaking the seal. Obviously you will still need to use the previously mentioned techniques as well, but it may help.

Good idea! I’ll leave them on the BBQ top rack for a few meals...... Can’t hurt.

[gmoss]

I've had good results with screw removers like these: https://www.acehardware.com/departments/tools/power-tool-accessories/screw-extractors/26177

First you drill through the stuck bolt with a bit that's about the size of the very tip of the extractor you plan to use, and then the extractor catches right away.

[jamesw]

I've had the same problem with 7 float bowl screws.

I drilled them out and re taped the hole.

6 x .75 thread (stock plug size).

No issues at all with any of them.

Re purchased drain screws from siriusconinc.com.

Good as new. 

Let me know if you want the correct drill bit size

[BenelliSEI]

I've had the same problem with 7 float bowl screws.

I drilled them out and re taped the hole.

6 x .75 thread (stock plug size).

No issues at all with any of them.

Re purchased drain screws from siriusconinc.com.

Good as new. 

Let me know if you want the correct drill bit size

Thanks James. I’ll give it a shot.

[Redline it]

a few months ago i picked up a set of carbs from italy. one of the bowls had a different bolt in the drain, and the strangest thing about that was obviously stock screw was stripped and the repair consisted of a small thin copper or brass tube was the insert and the new screw seemed to thread into it causing it to bite into the bowl. i got to thinking a cork or a rubber plug would probably work if it had the right taper. like a test tube plug. good luck on getting the pieces out.