Rounded off an exhaust header bolt.
The 2 outside ones loosened fine, the 2 inside ones just courteously changed their shape when I turned the allenkey.

2 Questions...

1. What's my best option for loosening? I've thought of...

-Filing flats on the bolt heads, not easy.
-Sawing bolt head in half and using a screwdriver/bit with ratchet.
-Drilling into the bolt, ..

2. Do I need specific bolts? they have a very deep head on them. can I use regular allen bolts?

__________________
PCV REPLACEMENT ECU WITH 04 WIRING LOOM STAGE1&2DNA GEL SEAT INSERT LOWERED 20mm FRONT+REAR CLUTCH ARM MOD
FORKSPRING SPACERS TALLER SCREEN THROTTLE GRIP CAM MOD DISTANZIAS 46TOOTH REAR SPRKT
SPEEDO HEALER 30MM HANDLEBAR RISERS TOPBOX MOUNT 08 XTX SORTED, ALMOST.
...SHEEPSKIN - Because a pain at the rear is not just a moany pillion.

Is your Allen key still in good shape ? or has this occoured because the corners have worn from the Allen key?

Without seeing the state it's in its not easy to suggest a fix as the fix depends on the state and what you have available to sort it.

Suggestions I would throw in are;

1) Before starting, make sure the hex bolt is clean, properly clean with no debris inside. Then try a new allen key (with nice clean corners on it), you might just have enough contact to remove it. I'd be inclined to leave it (bolt) soak for a while with a good quality release oil, before starting. The stuff Scaffolders use to service the fittings is very good for releasing siezed bolts.

2) Mole grips, if you can get good purchase on the offending bolt, if not I wouldn't even try it as you could make things worse.

3) Heat. Getting lots of heat into the bolt will help, but you need to be able to grip it first!

4) Screw Extractors/Easy Outs. As long as you can get a good grip on the tool, in a straight line, otherwise they tend to snap.

5) using an oversized Allen key, hammer it into the bolt, or if you have a Torx bit, they work too. Using an impact driver will help.

Just a few, I'm sure I'll think of more as the day goes on!

Good luck

__________________
>-------<

Never underestimate the power of stupid people in large groups.

hi mrfijjitt, darren has covered every base, very good suggestions!

if i was dealing with it- after a soaking in release oil try the over sized allen key trick if it failed, next the grips, then resorting to welding a bolt to the damaged fitting using a mig welder let it cool for a minute or so and then loosen, drastic sounding i know but between the direct heat and a decent grip it's the most effective

the fitting is basically a nut shaped like a sleeve, driven by a allen key. the stud coming out of the head allows for a strong reliable fitting. so i would avoid changing to a bolt style which can be more easily pulled out from the head causing worse problems, get on to yamaha and get new allen nut jobbies and new studs if nessasary

bernard

Following on from this, it's not necessary to use an oversize bit...

If you hammer the head of the allen bolt (this works particularly well with button head rather than socket head, but socket heads still work if you hit them hard enough x) so that the rounded off faces look like a hexagon again, hopefully a bit smaller and tighter than before...

Then hammer in an allen key so it is a really snug fit (a socket type one is a good idea as you can get more leverage, but it works fine with regular allen keys too, although it's a good idea to use some sort of extension bar, such as a plug spanner over the long end of the allen key, again for more torque/leverage)... you'll find more often than not that the impact of the hammering, together with the snug (interference) fit of the allen key in the compressed socket, will have the bolt free...

I have done this on a number of occasions... and recently won a significant bet, when a friend said it wouldn't work... she has yet to eat my deep fried sandal!

Jx

ps. if you are happy to forfeit the bolt and allen key, you can even add a dab of superglue into the socket before you hammer in the allen key - I did this earlier this week with a bolt on my mountainbike suspension that has resolutely refused to budge for over 14 years... once the glue had set, a bit of leverage and it popped out a treat!

__________________
"Where we're going, we don't need roads..."

JennyDakar.com

Or knock in a Torx bit into the damaged Allen Key head.

__________________
Click here to join the XT Supporter's scheme

Mods that I have done to my XTX's

My 04 XTX
Stage 1 & 2 DNA filters / Kev fuel mod / snorkel mod / Drilled air box mod / Engine breather mod / Fork Spacer mod / 15w fork oil /
[
My 07 XTX
Raptor 700 cylinder 102mm / Modified Crank Case to take a 105mm Raptor Cylinder / 11:1 102mm JE Raptor piston / Stage 1 Raptor Hot Cam / Ported head / Colder Spark Plug / +2mm Throttle body / DNA stage 1 & 2 filters / Modified Air Box / Snorkel removed / Worry Brothers stage 2 filter cover / 6mm & 8mm Bolts Replaced with Titanium Bolts / Recovered seat in Black / O2 Eliminator /

My 09 XTX
59HP at the rear wheel / Stage 2 Raptor Hot Cam / DNA stage 3 Air Box / Carbon Can Exhausts / Modified Exhaust Link Pipes / PCIII With Custom Fuel Map / Wideband Commander O2 Data logger / LCD100 Dyno Jet display & fuel adjuster / 2500 OHM HT lead instead of a 10K OHM XT lead / Extra Coolant Cooler / Protaper Fat Bars / Tail Tidy With LED Tail Light / OKE Protection Knobs / LED indicators / AIS blocked / Modified rear sprocket rubbers / Rear Foot Pegs removed / 09 ECU With 02 Sensor Changed To A 06 ECU / Complete wiring harnes Changed from 09 to 04 / Home made LED resistor flasher / Hole drilled in the fuel tank filler neck to allow quicker filling / Modified Bar End Weights / Progressive front fork springs, 15W fork oil, forks lowered 25mm, used XTR rear links lowering the rear 20mm, rear spring one click stiffer / Changed front & rear guards from blue to black / 47T rear sprocket / Speedo Healer V4.0 / Kev throttle cam mod / Throttle grip mod / The new 2010 O2 sensor mod is out, works a treat, The new 2012 O2 Controller is out, PM me for details

Now ride a 2018 MT09SP ABS + TCS

My KTM 990 SMR Mod book. http://www.ktmsmt.com/viewtopic.php?f=13&t=4946

Thanks people!
Enough help to get it sorted i'm sure....

__________________
PCV REPLACEMENT ECU WITH 04 WIRING LOOM STAGE1&2DNA GEL SEAT INSERT LOWERED 20mm FRONT+REAR CLUTCH ARM MOD
FORKSPRING SPACERS TALLER SCREEN THROTTLE GRIP CAM MOD DISTANZIAS 46TOOTH REAR SPRKT
SPEEDO HEALER 30MM HANDLEBAR RISERS TOPBOX MOUNT 08 XTX SORTED, ALMOST.
...SHEEPSKIN - Because a pain at the rear is not just a moany pillion.

also a slight tighten first can help
just brakes the crud

__________________
you win some, lose some, crash some
K+N filter, snorkel removed, homemade kev mod (with his blessing), co raised,
Pipeworx cans, r1 led back light, under tray removed, small indicators, handguards, cnc short levers,