Broken Carb Holder Screw

doing some work on a KZ1000 that i picked up... long story short, i twisted the head off one of the carb holder screws.:sick: the last one to be removed. there is about 1/16 to 1/8 inch of the screw exposed.

i have sprayed a god amount of penetrating oil onto the screw, but i doubt it will do any good.

the engine is still in the frame... but that could be changed. what are my options?

some of my ideas.
1. dremel a slot in the remaining screw material and try to bust it loose using my impact driver. maybe add some heat (i.e. blowtorch) to expand the aluminum.
2. try one of those screw extracters. again, maybe with some heat.
3. replace the cylinders.
4. something else.

frustrated... im going to bed.

~mike

try heating up the aluminum around it a little,tap whats left of bolt with a hammer and blast it with some wd40 while its still hot;)

If You're going to cut a notch in the screw shaft,make it a phillips cut instead of just a flat slot.You'll get a better grip,and less chance of it splitting.
Also...I've read a few times(mostly on the old forum) where Guys have dripped melted wax into stuck screws/bolts,etc...some had great success with it.I've never tried it(been lucky),but thought I'd mention it.

Sandy, I face similar screw extraction problems on a daily basis... MOST of the bolts and screws on a BS34 assembly will be galled and refuse to come out without persuasion. Heat does help BUT there are usually too many that need extracting to heat. The best thing I have found is to cut a flat slot for the large flat bladed screwdriver. Trying to cut an X and have an impact driver bit stick is pretty tough. The #2 impact driver bit almost never works well on really stuck bolts/screws... the #3 with much deeper and thicker cuts works OK but I have found the flat driver bit works easiest and best for me. When you cut the slot, take care to make it deep and even and have the bit seated in the slot firmly. Use a large and heavy hammer and make the first strike firm... This will generally break it loose. Since there is only one bolt in question, I would use some heat as well. The bole you speak of would be a pain to drill because of its location and taking the engine out will probably make it a bit easier chore. I wouldn't disassemble the top end since the engine will come out as easily as pulling the head with it in.

I think,like You said George...making the first hit count is going to be the key.
Too many people assume that it's good enough,or They don't concentrate,or prepare enough for that first hit,and end up making a mess.

Mp3z24 wrote:

. . . there is about 1/16 to 1/8 inch of the screw exposed.

4. something else.

I would try a pair of GENUINE Irwin Vise Grips on that stubbie. Get your test fitting / clamping done on a loose bolt first. Make sure it is clamping HARD. Rock / wiggle it back and forth to maybe loosen it.

The heating is a good idea, too.

I had this exact problem with a Z750 the only difference was that the screw was about three mm into the head, the first thing I done was drilled a 2mm hole right through the screw and sprayed WD40 through the hole but the screw was still held tight. I then made the mistake of trying an EZout that broke leaving 2mm of exposed metal. After plenty of colourful language I got a dremel and a diamond cutter and drilled the EZout and the screw remnant out I then drilled the head to 5mm and Helicoiled it and it works fine. Hope this is some help.

well, i think it is f-ed now. tried some of the suggestions this weekend.

soaked a ton of liquid wrench on it and gave it a few whacks with a hammer... let it sit overnight. dremeled a slot in the screw, used my impact driver, and nothing.

tried heating the aluminum around it with a propane torch. hit it again with the impact driver / hammer and nothing. all i managed to do was break off most of what remained outside the cylinders.

tried heating and hitting it on an angle to try and spin the screw out, and nothing.

so, now it is all but flush with the mounting surface. all that remains is a little nub that didnt break off when i tried the impact driver.

i guess i've worked away my options and i will have to drill it out, and helicoil it... doh.

~mike

Post edited by: Mp3z24, at: 2007/04/16 12:18