Seized exhaust nut removal suggestions?

[john jupiter]

Hi Guys, I have a completely frozen exhaust nut and the correct wrench which has been used to attempt removal but no result. Does anyone have a good method for removing on of these? Heat? How much and where?
Braze to the nut?
I'm stuck...

[Bevel bob]

Undo the silencer from the frame and use the whole exhaust system to help move the nut ALONG with a long exhaust nut tool, You could also get the motor hot and cool the nut with chilled water from the fridge/freezer to get the differing expansion to help.

[john jupiter]

Bob, thats sounds like a really good idea. I forgot to mention that engine is apart and the head is removed from the bike which was a non runner for a long time

[DewCatTea-Bob]

[quote= john jupiter ...
" the head is removed from the bike "

____ The cyl.head may be removed from the 'bike', but if it's still mounted to the engine,, then you could have someone hold-down the motor whilst you try to loosen the ex.nut, by turning/twisting the ex.header-pipe along-with your effort of trying to turn-loose the nut using your ex.nut-tool.
Assuming that the whole motor is resting on the ground,, it'd be best if the ex.pipe was first repositioned* from it's usual 7-o'clock position to a 4-o'clock position. _ That way, when the header-pipe is attempted to be turned counterclockwise (along-with the ex.nut), the weight of the motor will then help hold itself in place while the ex.pipe is lifted & the ex.nut is loosened.
(* Even-though the ex.nut may be frozen/stuck in place, the ex.header-pipe can still always be rotated-around anyhow,, so although it may be difficult to rotate the ex.pipe to another position, it can still be done [despite the amount of pressure being exerted by the ex.nut] !)
__ Although the motor would be even-more stably held-down in place whilst the header-pipe is being twisted rather from a near 8-o'clock position,, I didn't suggest that additional advantage because I suspect you'd then run-out of maneuvering-space that-way, (as the ex.pipe would then possibly become rotated too close to the level which the bottom of the motor is resting down-on).
However, 'that-way' may actually work best of all, (and with no helping-hands needed !),, if the whole-motor is then laid-over onto it's left-side (atop a few layers of cardboard). _ Cuz THAT-way, you'd then have additional maneuvering-space (for the ex.pipe to travel), AND-also the motor would then definitely stay-PUT (while the ex.pipe is rotated [from it's pre-set 8-o'clock position] towards ground-level [whilst the ex.nut is loosened]) !
__ I've run-into some really stubbornly frozen-STUCK ex.nuts before, but I've never had this-method* (of loosening the ex.nut), fail for me !
(* Meaning the 'method' of turning the ex.pipe along-with the ex.nut.)


Hopeful-Cheers,
DCT-Bob

[john jupiter]

That is great advice and i will certainly remember that if i get a seized nut that still has a header attached. Unfortunatly it has been hacked off. I can mount the head to a fixed table for leverge but the nut will not budge so far.

[DewCatTea-Bob]

[quote= john jupiter ...
" i will certainly remember that if i get a seized nut that still has a header attached. "

____ It seems you should've included a picture of exactly what you were actually working with, so that we then wouldn't be left to assume otherwise.



" Unfortunatly it has been hacked off. "

____ Let this be a lesson to those newbies who start any such process before informing us of their considered intentions !
__ Since your endeavor has been important enough to destroy the ex.pipe,, then somewhat likewise, why-not drill a hole through the ex.ring-nut & ex.pipe and insert-through a pry-bar to which you can then over-sert a length of water-pipe with enough extended-leverage to twist-loose that sucker to-hell !?



" I can mount the head to a fixed table for leverge "

____ That's fine, so long as that works at-least a securely for you (as being reattached to the engine-motor).



" the nut will not budge "

____ Did you yet try-out any hot & cold shocking procedures (such as b.Bob has previously suggested) ?
It may take more than just one attempt at such,, so try directly heating only the head's ex.nose, until the ring-nut gets (indirectly) mighty piping-hot as well,, and then insert an ice-cube inside the pipe whilst applying another piece of ice against the outer-edge of the ring-nut, and then see if that temp.shocking-step doesn't help do the trick of freeing-up the stuck nut.
__ Alternatively, perhaps you could possibly reshape* the ring-nut into having effective-sides sort-of like a standard-nut and then put a (1/2" or 3/4" drive) socket over it and use an impact-driver (to drive it all loose) ?
(* 'Reshape' by removing only the fin-tabs that would be in the way of 'fitting' a metric or std.drive-socket [over the then hex-shaped ring-nut].)

____ Don't feel too bad about this particular happenstance-issue which you find yourself facing,, as I know others have already-before had to deal with the very-same exact circumstance, (hacked-off pipe & all) !


Hopeful-Cheers,
-Bob

[john jupiter]

Thank you for the suggestions, some very good ones for sure. It is too bad that the header pipe was not able to help make this process easier but i will surley note this for future.

I should have stated that the head this was performed on is a 59' 125 sport that was heavily corroded from being left outside in the northeast for over 40 years. Severe corrosion in the exhaust tract occured and the aluminum looked like ragged, blistered concrete.
The head was also badly damaged during racing and is too expensive to repair. i already have a replacment head for the motor but i wanted to remove the exhaust nut from this head and modify and use for a living room display.

I tried drilling through and putting a steel rod insert through the hole to apply leverage with a water pipe to get it to turn but no such luck. I tried applying a huge pipe wrench on the nut but that only resulted in the brass being chewed away.
What i finally did was cut the remaining header pipe into three wedges with a reciprocating saw. Then pried them out with a chisel, hammer and pliers. Then i was able to get to the actual brass nut which i again cut a 1/2-3/4 inch slice out of and then removed with chisel and hammer. After the small piece was removed from the nut , i put the nut into a vice and colapsed it. It fell out of the head. Threads might even be ok.