Seized Exhaust Header Nut

[montmil]

Have you tried with a bit of "rapping" before putting the torch to it?  I have done two chains (r65 and r100) and neither one required any heat.

Planned to try that first. Torch second. Third option? Like my 'stan-deployed son sez, "There's nothing that can't be fixed with a small amount of C4."

Monte

[Bob_Roller]

I don't remember having any difficulty removing the front case, a little tapping with a plastic faced hammer, and a brass drift, got the job done .

On reinstallation, heating up the area where the bearings rests, with a heat gun, would be a good idea.

I personally don't like using a torch on cast aluminum.

[Justin B.]

I agree, Bob, I always try the $9.95 HF heat gun first.  I was mildly surprised with it's performance, it heated up the transmission case and cover nicely when removing the bearings.  I think the Haynes "Liars Bible" I have suggests you may or may not have to heat the case...

[nhmaf]

I am very pleased with all the uses I've found for my ACE hardware heat gun, though I think I paid $11.99 for it.  I agree with the guys - try a heat gun before a propane torch - it is much more controllable and less prone to setting nearby things alight !

[Lucky_Lou]

Here is a tip for large seized threads on pipes ect drill a shallow groove any where you can just the point of the drill.
Liberaly squirt round with an antiseize compound replace the drill with a steel rod slightly smaller than the drill size switch the drill to hammer located it in the pre drilled groove and vibrate away this technique works on alot of the old pumps and motors i have the pleasure of repairing i know the exaust flange is alluminium not steel but i think it would probebly work, this pretty handy on sensitive gear when you cannot use heat ie hollow shaft motors ect
Lou

[nhmaf]

If you find that you still need to do some thread filing on the exhaust threads - I would recommend this handy little external thread file that I bought at a local auto parts distributor.   They have an SAE file and a metric file - you want to get the metric one for working on these bikes - use the 2.00mm side which seems to be a perfect match for the exhaust thread pitch/depth.   The valve cover and USA air-plumbing bits can get in the way a bit due to length, but I think that it may save you some time and improve your accuracy of remaking thread grooves over a single tri-corner file.



Here is a pic of the semi-galled threads on the right head of my R65 (the left head is good) after a short amount of cleanup with the thread file.   With more time I think it it could come out better, but at the moment, I've got an exhaust nut that goes on and off nicely and holds tight, so I'm not going further until I have to!



while I don't pull my transmission off to clean and lube the input splines every single year, I DO make sure to remove the exhaust nuts, clean them and the heads threads, and re-apply some silver anti-seize every year !