[Squeeky]

Tried removing the 5 mm hex bolts under the plastic cap on the handlebars of a 2017 GL1800 near the clutch reservoir to install a phone holder. Bottom bolt came off after overcoming reasonable factory tightening with normal results. Upper is a PITA. Tried multiple 5 mm hex wrenches to ensure I wasn't rounding them off. Drove the hex in with a hammer when it started to round off, then a baby sledge to regain a bite with the hex wrench. Tried an impact driver with a phillips bit. Let WD-40 soak in. The hole is rounded now. Wasted money on a titanium speedout screw extractor set. The drill part was non-effective so the gripping reverse threaded end couldn't get a grip. Considering cutting a slot with a fein multitool or grinding a slot with a dremel tool. Haven't tried heat yet. Any other ideas besides parting out (grin)?

 

[Pooch]

Maybe try drilling a smaller pilot hole in the bolt and try smaller bolt extractor?? I don't know, just guessing.

 

[Zee Fifty]

I would drill the head off with a drill the same size as the bolt shaft. Take it a part. Then try to remove the bolt from the part. If you can’t I would drill it out at the minor diameter and clean the threads up.

 

[Fluke189]

Some don't like electric or air impact drivers, but they along with good hex impact sockets work wonders on these tough bolts, but too late now if the hex is rounded. Best bet now is drilling. Get a bit just slightly larger than the threaded part of the bolt, drill into the hex head til the head pops off. This is usually easy as the hex hole is centered and it doesn't take that much drilling to pop off the head. Once the head is off usually the bolt is easy to remove with just pliers.

 

[OnaWingandaPrayer]

Now that the hex is rounded out, you might force a Torx bit in and have another try that way before drilling the head off.

 

[Destindoc]

I too have found screw extractor sets to be worthless. I had the screw on the hand brake fluid reservoir cap seize up, apparently the top of the screw seizing to the cap... don't know why, I've had it off several times. But I rounded it off and was using JIS screwdriver at that.

Did drill out the head very gentle, then the cap came off and the remaining screw came out just fine. Replaced with a little anti seize to it. I'd drill out the screw cap just very gently, slowly until it is gone, then pull it apart. You may also find the screw threads themselves are not what is seized.

 

[GoldWingrGreg]

Either drill the head off, or remove the handle-bar switch and use a dermal with a cut-off wheel. If you need a used mount cap and bolt, I probably have used ones I can send you for free plus shipping and the padded envelop.

 

[philipintexas]

Sometimes, if there are two bolts holding something and one is stubborn, replace and tighten #1 then try to remove the stubborn one. Takes some of the load off the tight one.

 

[Waldo]

You can "fudge" a JIS screwdriver by grinding the tip off a "regular" driver until they look like these. I have discovered that the Kobalt phillips #2 bits from Lowes are a perfect fit for JIS screws. They lock right in. Get 25 for $5.

Yay! I get to sing my song again!

A battery impact is invaluable, especially for breaking loose the factory screws that are frozen in place from dissimilar metal fusion. Excellent if you don't have air impacts. I'm gonna sing this hymn until everyone gets religion. A simple use of an inexpensive battery impact will get most screws out and most screws in including those in the tail lights. Honda's screw heads are made of reconstituted rust, I swear (often used to swear but not since I got an impact).

I picked up a set of the shown 10.8 Makita for $89 refurbished. Search google or >CLICK<

Get the ones with the small battery so you can get it into tight places. No need for a larger one. This one will drive 4" deck screws into treated wood all day long. This one will get your trunk light nuts off without breaking the plastic. They will get out your res screws too. NOTE: this impact is NOT going to loosen your wheel lug nuts and it's silly to think that it will.