Topic: Exhaust Stud Broken... Causing Exhaust Leak

[mike665]

I am a new CB650 owner and when replacing the exhaust to a 4-1 notices that the stud for the exhaust flange is completely busted. It has enough left to hold the pipe in place but at times I can see some exhaust coming out--I also am getting some backfiring.

Any suggestions on ways to fix this? I am pretty handy but cannot weld. Thank you in advance.

[Grabcon]

If it was my bike I would find a good heliarc (TIG) welder and bring the bike to him to weld. I would remove the exhaust and let him weld it up, I then would finish the face with a small grinder, redrill and tap the hole. A good welder should be able to do this with the bike together.

The drilling of the new hole could be difficult but take your time and drill straight. I would figure out how to drill and tap before I bring it to some one to weld. Clearance maybe an issue you my want to think about removing the front end for good working room.

[mike665]

Thanks Grabcon!

The bike is backfiring a bit and I am not sure if this is the issue causing it... Knocking out one issue at a time.

[Grabcon]

You are welcome. If the exhaust leak is to bad I wouldn't run the bike till the leak is fixed. If the leak is really bad you could burn a valve. don't want to do that.

Let us know what you end up doing.

[bender01]

Could you space up the missing area with some washers? Would that create enough seal when tightened? Did you replace the exhaust crushwashers with new ones with the new exhaust? They are cheap and add some space!

[bollingball]

Spacing would not give him more meat for the threads to bite into it would just cover up the bad area you see not a option.

[bender01]

I wasnt sure it was stripped yet but it looks like it might be.

[bollingball]

Take out that bad stud and a good one. Use a depth gauge from a mike. to compare the two holes ignore the fins you need to know how deep the threads are from the known good to the bad one. Then look at both holes to see if one is larger outside diameter than the other. This will give you an idea of what is going on If you go with the insert  I would definitely go with a Timecert. If any other machine shop work needs to be done to other parts of the motor then have it fixed liked Grabcon said

[Grabcon]

Hey it's been a month. What did you end up doing to fix the exhaust stud?

[RAWNOG]

http://www.bikebandit.com/houseofmotorcycles/1975-honda-cb550k1/o/m9232?q=90044-323-300#sch400408 - part number 27 BOLT, STUD (6X40)
I think thats the correct part but im not sure, heres a few of my search results:

http://www.ebay.co.uk/itm/Honda-CB550-K3-77-78-Exhaust-Studs-Nuts-Pair-/150514644601?_trksid=p4340.m263&_trkparms=algo%3DSIC%26its%3DI%252BC%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D15%26pmod%3D150514644936%26ps%3D63%26clkid%3D1038268036492123854&_qi=RTM796044#ht_1180wt_905

http://www.partsnmore.com/parts/honda/cb550/?filters[category]=hardware&filters[price]=50&filters[per_page]=25

http://www.bikebandit.com/search-products?q=720526

Are ANY of these right? I dont care about the price at this point, Im not drilling, welding or retro fabricating around a piece of hardware plus I can't the tools to do so.