Removing stripped boot bolt

This allen bolt has been stripped. So, how to best remove it? I have taken a dremel and cut a slot to use a flathead screwdriver to remove it. So far, it won't budge. I've used some kroil on it too. If anyone has additional ideas, I'm all ears.

 

I'd use heat. If you need the carb holder cut the head off the bolt and remove. Heat the head and remove with locking pliers.

 

have you used a vise grip to add more torque to your screwdriver? otherwise, just use the vise grip on the head.

 

Left hand drill bits will help. Screw extractors are not my friends, so I would stay away from them. Seriously though, get a small heat gun, or a hair dryer if that is all that is available, warm the aluminum around the bolt until you cannot comfortably touch it with your fingertip.
Btw, be sure to keep a rag or something over the head to keep swarf (metal shavings) from getting inside your engine if you do any drilling, cutting or grinding on that bolt.

 

Heat and an impact driver.

 

From what little I can see in the picture, the boot doesn't LOOK bad. If it's NOT bad, don't mess with it. You're gonna create a bigger headache for yourself WHEN the bolt breaks off.

So.....my question is just: Why are you taking the boots off?

Dave

 

Right - so this is a Maxim 400 I'm parting out. So, I'm taking everything apart as requests come in.

I have torqued on this thing for a while with the vise grips, but no dice, even after heating the backside of the bolt with a propane torch. so at this point, I think I might use a dremel cutoff wheel and take the head bolt off. Once I slip the carb holder off, at least I can get more penetrating oil into it, and have an easier time torquing on it.

 

Or you (or the new owner of the head) can have a more expensive time having a machine shop remove the bolt. Even odds.

 

Had the same issue with 6 of the 8 bolts and the heads all snapped off. Brought it to my Chevy dealership where I work and had my mechanic co-workers use a air grinder with a small tip after they used 2 left hand bits and 6 other bits that all broke... finally got them all out! Now you will have to get a M6 x 1.00 helicoil kit. Once those are all in, it's like brand new! Go buy stainless bolts to replace the old ones.

 

It's funny how it all ended up: after it just refused to budge, I used my dremel cuff-off tool to cut through the head of the bolt as close as I could get without burning into the rubber of the boot. Then I bashed it a bunch with a punch thinking I'd snap it off, remove the boot, and then use vicegrips with some penetrating oil. But after bashing it a bunch, it started to turn and was removed with a screwdriver. A friend told me that just whacking stuck bolts with a hammer often frees them up. Go figure.

 

It often breaks them off, too