Right, I have removed the exhaust from my 2003 XT600E but at the cost of snapping off two of the studs. One is right where it goes into the head so, I assume needs drilling out. The other one, awkwardly placed behind the frame downtube, has all of the stem still in place but I cannot shift it! I have sprayed it with ACF50 and applied a bit of heat but it wont move. Any helpful tips??
That will need some time.
Respray it twice a day for a week.
Try to move it both directions every day.
Whats your workshop setup? Do you have a MIG/MAG/TIG welder? Do you have a friend with a welder?
Best bet is to weld a nut onto the stump then remove the one behind the downtube.
Then fabricate a drill guide (metal or at least hardwood), bolt it to a cleaned thread next to it (would be better to use 2 or three bolts)
then drill the other stump out, starting with a center drill and following with bigger diameters. Ideally use left handed drill bits, if they catch they will move the bolt outwards.
If you can get a clean 3,5 mm hole into the bolt you may try hammering a torx bit of size TX25 home and try turning the bolt with that bit. I recommend the best quality I can find, I have a German Hilti torx bit just for that.
Thats expert level stuff really. If you are not up to the job failure is almost certain, as the studs are steel and sit in a soft Aluminium alloy thread. Better chance would then be to remove the engine and let a machine shop have a go, without the downtube in the way.
Best of luck!
Andy
PS for later: Do not use original parts there as they will not hold up (they just rust away).
I always go for zinc plated studs if available (small engines may have them for carb or exhaust, they are standard M6 thread) or remove the head from a zinc plated M8x40 bolt and use that as a stud. And I use copper plated nuts.
It is a good idea to use ceramic paste for assembly.
Chop your own wood and it will warm you twice (Henry Ford)
I don't have any welding facilities at all. My local bike workshop is going to have a look to see what they can do.
I will keep spraying anyway. I have drilled out broken bolts before but the left hand drill idea sounds good. I have some stainless studs to replace the mild steel OEM rust bugs. We'll see how we get on.
motorang wrote: Tue Nov 24, 2020 4:27 pmBest bet is to weld a nut onto the stump then remove the one behind the downtube.
Yep what Andy said, weld a nut or just weld on to the stud & grab the weld with molegrips then wiggle it out, and then drill/tap them all out to 8mm & replace with stainless studs.
Mezo.
"A wise man makes his own decisions, an ignorant man follows public opinion"
I don't have any welding facilities at all. My local bike workshop is going to have a look to see what they can do.
I will keep spraying anyway. I have drilled out broken bolts before but the left hand drill idea sounds good. I have some stainless studs to replace the mild steel OEM rust bugs. We'll see how we get on.
Be careful with stainless steel, as this can give galvanic corrosion. I'd stick with galvanised studs as motorang said! In my XT600Z I've replaced one with an mate stud, as the thread was buggered.
You'll probably end up having to take the head off I reckon... one of the bikes I bought had something similar, the previous owner had tried to drill out 2 broken studs, but he completely messed it up by drilling down the side of the old studs... it's a really hard thing to do with the engine in the frame.
I got a machine shop to fix it up for me... I always use stainless studs to replace the old ones, but make sure you smother the threads in copaslip before you fit them.
