Author Topic: XT600 Sorting out the exhaust stud  (Read 1696 times)

squirrelciv

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XT600 Sorting out the exhaust stud
« on: August 23, 2010, 06:18:29 PM »
Some may remember my quest for assistance regarding a bodged repair attempt by my bikes previous owner. Our would-be mechanic managed to add to the already sorry situation of a sheared exhaust stud by snapping off a small diameter drill bit partway through the job.

Furry John kindly lent me some diamond tipped grinders for a dremmel to see if the offending drill bit could be ground out, but sadly that didn't work. So I've gone for the obvious (but pain in the ar5e) approach of removing the head and seeking professional assistance.

SteveH very kindly offered his SV as a loan bike while the XT was off the road and added the use of his garage, tools and considerable experience/assistance to remove the cylinder head. Saturday was the chosen date and I got to Steve's around 9am. After a cuppa it was off to the shed. It was a great help having SteveH there because he knows the Yamaha engine so well. We managed to remove the head with the engine still in the frame. It was fiddly but do-able.

I really hate that first glance down the barrel or under the rocker cover. What will I find?? Are the cams chewed?? Is the barrel scarred?? Nothing to fear with this one, all looked absolutely mint. ;D Steve (being Steve) got the micrometer and dial gauge out to confirm what the eyes suspected. Things were so 'within spec' that we are pretty sure someone had been in there before us and replaced some parts.

Next part of the repair is to get the head to a engineer mate in Cardiff who assures me he has suitable weapons to remove the broken drill bit and remaining stud and replace it. While he's there he's offered to whip out the valves and re-seat them if needed.

Shall keep you posted and let you know about the re-build as and when. Big, big thanks to SteveH. Extremely greatful matey.


PS, isn't the SV fun to ride. ;D
Live long, live well, live happy

el vencejo

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Re: XT600 Sorting out the exhaust stud
« Reply #1 on: August 24, 2010, 08:28:20 AM »
Spark Erosion is the way to go.  ;)
Of course it is also the most costly  :'(

guest868

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Re: XT600 Sorting out the exhaust stud
« Reply #2 on: August 24, 2010, 10:02:25 AM »
Good to see some progress fella.

squirrelciv

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Re: XT600 Sorting out the exhaust stud
« Reply #3 on: August 24, 2010, 05:54:55 PM »
I'll miss the loud backfire when shutting off the throttle. Loads of fun when your filtering through the early morning commute ;D.

Just a note, the valve port that lost the stud [and subsiquently was blowing] did show some signs of over heating. It was quite markedly discoloured, which tells me not to leave these little problems so long next time.
Live long, live well, live happy

Steve H

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Re: XT600 Sorting out the exhaust stud
« Reply #4 on: August 24, 2010, 06:22:45 PM »
PS, isn't the SV fun to ride. ;D
Yep it goes well.