Re-installing exhaust after having the Y-pipe TIG welded. Having a bitch of a time torquing down the lower flange nut. Anyone know what size (thread pitch and count) in case I round it off and need to replace? Loaned my thread gauge and never saw it again. I guess I could just take it to HD, but was hoping someone here knew what was right. I'm thinking of using a hex nut and washer instead.

Also, I'm using a few combinations to try to get at it (deep-well socket, different length extensions). Have the O2 sensor out so it doesn't block me. What tool do you guys use??? Such a PITA!

I'm also having an issue getting the bracket clamp flush. I've backed it out and re-seated it a few times. Not being able to gain purchase on the lower flange is keeping me from installing it flush.

Thanks, ya'll!

BTW, dealer wanted $460 for new Y-pipe and install. So far I'm in for $40 and just have to button this up right.

 

here's specs from the 09 manual, not as tight as you would think:

Tighten the exhaust system as follows:
a. Tighten the top nut of the front cylinder head exhaust
flange to 9-18 in-lbs (1-2 Nm). Tighten the bottom
nut to 100-120 in-lbs (11.3-13.6 Nm). Final tighten
the top nut to 100-120 in-lbs (11.3-13.6 Nm).
b. Tighten the bottom nut of the rear cylinder head
exhaust flange to 9-18 in-lbs (1-2 Nm). Tighten the
top nut to 100-120 in-lbs (11.3-13.6 Nm). Final tighten
the bottom nut to 100-120 in-lbs (11.3-13.6 Nm).

I gotta couple of wrench combos i use- depending on the bike, I have crowfoots

a 1/4" drive 1/2" works well for some of the nuts


Mike

 

The nut is 1/2", stud is 5/16x20 threads per inch. Standard 5/16 , they do make over size studs for inserting into helicoils into the heads, but if you have never been there it should be standard corse thread. Don't try to use a hardware store nut, heat will cook it in a few runs. Need actual exhaust rated fasteners. They are made of a bi-metal compound that resists heat issues. (hot cold cycles all the time)

 

You won't round it off if you only torque it 10-12 ft. lbs.

 

3/8 drive 6 point swivel socket and 6" extension works for me. Not deep well. With this low torque a Harbour Freight socket should work forever.

 

Sounds like you need a manual, a good inch pound torque wrench, wobble extensions, and then you will have the tools you need to do the job properly. Torque to specs, take a few rides, then re-check the torque. Never over torque these nuts.

 

So, on my way home from Sturgis (had a great time as always), the exhaust gets loud. At a gas station I notice the top nut fell off the top stud, front cylinder; a leak. No biggie, its happened b4. I've got a service & parts manual for the bike (2007 FLTR). I found these threads.
Thanx for the help!

No damage done riding it on 2 tanks home I'm guessing.
I'm thinking about replacing that nut with a nylock nut,is that too much heat there for a nylon insert nut? "Locktite is your friend"

 

Never Seize is a better friend

 

I just googled this and he tells me it's good for 250 degrees,

rk classic.

 

you could take off the other nut and go match up at a hardware store.