hi i am trying to remove my barrel on my dt125r i have removed the hed and 3 of 4 nuts securing it 1 of the nuts is extreamly rounded and i cant remove it has any one got any idia how i can remove it it is the nut that also holds the clutch cable tentioner so it is under a lip so i cant get to it with extractor tools

There are self adjusting spanners you can buy which grip tighter the harder you push on them. I have a set of 5 different sizes which I use for stuff that's realy badly rounded off and they never fail even on nuts that are completely round ! If you can get a normal spanner on the nut in question then one of these jobbies should go on ok. I just wish I could remember their proper name so you know what to look for, sorry.

The thing you need for this sort of job is the Aston Super Wrench, there is a large set on eBay :

http://cgi.ebay.co.uk/NEW-6-PCE-SUPER-WREN...0105127001r5847

but you can get them individualy from other places, have a search on Goolge.

These are a must have for any tool box, one of those get-you-out-of-jail-free tools.

Moe grips should work nicely,

dremall moto tool with a cut off wheel works great , cut a slot and use an impact.

ive never found mole grips to work effectively on head bolts, there isnt enough access.

i think the self adjusting wrnechs refered to are actually called "Stillsons" or Pipe wrenches, i used a pair at the weekend to get a stuborn exhaust nut off and also to get the sheared bolts out of my reed block

http://cgi.ebay.co.uk/HEAVY-DUTY-PIPE-WREN...%3A1|240%3A1318

the above example is the type of wrnech i meant, not sure how effective this would be on an engine head as on my DT50 the nuts are hidden between the fins.

you may end up having to heat it up and crack it to remove it, but be carefull not to damage the threads on the stud it screws onto

I will be amazed if he can get a pair of stillsons on any of his head bolts, they're huge man !

Those are the same or similar spanners I've got in gas up let's go's link, super wrench.