Exhaust Stud

[Scotty]

Ultima list the OEM part number 16715-83 as being the same as their stud 66-242 so you should not have a problem based on that.

[Deye76]

Ultima list the OEM part number 16715-83 as being the same as their stud 66-242 so you should not have a problem based on that.

Also thanks JW113

[Deye76]

Another question, if chasing threads inside a head where this interference stud is going is a special tap needed, or will a conventional thread chaser be OK?

[JW113]

That's a damn good question, and have no idea. But if you look closely at the threads on the bolt, you can see that they are formed with a "double edge", for lack of better description. So I imagine that threads in the aluminum hole are standard, and the bolt threads jam themselves in.

I've only had to replace an Evo exhaust stud once, and in fact had to fix a stripped hole in the head while still on the bike. Was not a particularly fun experience, as I recall. Used LOTS of red loctite on the stud.

-JW

[david lee]

That's a damn good question, and have no idea. But if you look closely at the threads on the bolt, you can see that they are formed with a "double edge", for lack of better description. So I imagine that threads in the aluminum hole are standard, and the bolt threads jam themselves in.

I've only had to replace an Evo exhaust stud once, and in fact had to fix a stripped hole in the head while still on the bike. Was not a particularly fun experience, as I recall. Used LOTS of red loctite on the stud.

-JW

thats where helicoils come in handy

[FSG]

Another question, if chasing threads inside a head where this interference stud is going is a special tap needed, or will a conventional thread chaser be OK?

Yes, it's what I've used in the past, none have gone on to be a problem

remember to use a ball inflation needle or similar to blow out debris from the back of the hole

[Deye76]

Another question, if chasing threads inside a head where this interference stud is going is a special tap needed, or will a conventional thread chaser be OK?

Yes, it's what I've used in the past, none have gone on to be a problem

remember to use a ball inflation needle or similar to blow out debris from the back of the hole

OK good because without thinking first I used a conventional chaser. 

[thumper 823]

If you use BRASS  nuts you will never ever have this problem....
I double nut them

[JW113]

You might if your exhaust bracket breaks and the pipe is hanging on by only the studs...

-JW

[david lee]

cant understand why shovels didnt have the 2 stud set up

[Hossamania]

cant understand why shovels didnt have the 2 stud set up

Because one stud was a step up from a spring to hold it in place....

[thumper 823]

You might if your exhaust bracket breaks and the pipe is hanging on by only the studs...

-JW

I do not see how a brass nut would have anything to do with a busted bracket.
If you have a crappy bracket and it brakes then it will be hanging no matter what you use for a nut.
A brass nut will not seize to a stud .
S.S. will .... they will gall  (develop seized spots.)
Personally, I have not ever had it happen.

[Deye76]

Yeah the key to not breaking studs is a really good mounting bracket(s). I've not ad any problem with the OE flange'd nuts. I use a little copper anti-seize on them, and re-torque after initial installation. Anti-seize doesn't make them come loose, only prevents galling. If the exhaust has not been off the bike for a year or more, I use a little heat, and penetrating fluid on the nuts.

BTW the the interference threaded stud went in like buttah.

[JW113]

I do not see how a brass nut would have anything to do with a busted bracket.

That's because you missed the point. Brass nuts won't prevent stud damage if a bracket breaks. Agree? My softail exhaust bracket cracked, and the rear pipe was hanging from the studs. It caused one of them to pull loose in the head. Nothing to do with the nuts, and in fact I've never used brass nuts on the exhaust studs and never had one seize. I'm sure there is no harm from using them, but I don't see any necessity either. I'm guessing the engineers that designed the things didn't either.

-JW

[thumper 823]

I am sure you know the difference between
engineering
Freeze

and then the bean counters.

I have saved my arse quite a few times using SS nuts .
Most other places have had to jig up and do the dirty deed of getting a stud out.
The Harley for argument- is a bean counters toy too.
nothing escapes them.
To each their own.

[david lee]

cant understand why shovels didnt have the 2 stud set up

Because one stud was a step up from a spring to hold it in place....

wow ive learnt something else a spring ?

[Hossamania]

cant understand why shovels didnt have the 2 stud set up

Because one stud was a step up from a spring to hold it in place....

wow ive learnt something else a spring ?

It was more of a joke, but many exhausts were and still are held on by springs, especially dirt bikes, possibly even some sport bikes, it allows the pipe to be a bit flexible when bouncing around, instead of rigid and prone to breakage. I'm not sure that any of the really old Harleys were held together using springs, but it would not surprise me.

[crock]

cant understand why shovels didnt have the 2 stud set up

Because one stud was a step up from a spring to hold it in place....

wow ive learnt something else a spring ?

It was more of a joke, but many exhausts were and still are held on by springs, especially dirt bikes, possibly even some sport bikes, it allows the pipe to be a bit flexible when bouncing around, instead of rigid and prone to breakage. I'm not sure that any of the really old Harleys were held together using springs, but it would not surprise me.

My old Pan Head was held on by luck   

[Hossamania]

cant understand why shovels didnt have the 2 stud set up

Because one stud was a step up from a spring to hold it in place....

wow ive learnt something else a spring ?

It was more of a joke, but many exhausts were and still are held on by springs, especially dirt bikes, possibly even some sport bikes, it allows the pipe to be a bit flexible when bouncing around, instead of rigid and prone to breakage. I'm not sure that any of the really old Harleys were held together using springs, but it would not surprise me.

My old Pan Head was held on by luck   

Now that made me laugh!

[david lee]

cant understand why shovels didnt have the 2 stud set up

they got me but on a serious note when i got my 80 shovel back in 84 within 2 weeks both pipes fell off and stripped the threads.used helicoils and still there today

Because one stud was a step up from a spring to hold it in place....

wow ive learnt something else a spring ?

It was more of a joke, but many exhausts were and still are held on by springs, especially dirt bikes, possibly even some sport bikes, it allows the pipe to be a bit flexible when bouncing around, instead of rigid and prone to breakage. I'm not sure that any of the really old Harleys were held together using springs, but it would not surprise me.