exhaust stud

[pudvah]

If my exhaust isn't tight at the manifold beause one of the exhaust studs is stripped, would that cause a high/hanging idle? technically its an air leak so I would assume so. Yesterday I was changing my A arm bushings and when putting the exhaust back on one of the studs just would spin causing me to not be able to tighten it all the way. After I got it back together the idle would hang for a while after blipping the throttle. I plan on fixing it today or tomorrow but Im hoping thats what is causing it.

 

[jus_me]

It would cause a lean cond yes. Is it leaking real bad or just a lil bit ? I know you prob have but I have to ask, have you performed a leak test lately ? If it ran fine before you removed the exhaust and now it is hanging and you know its leaking I would say that's it. If it does it after you fix it than I would do a leak test. It wouldn't hurt to do one now since the exhaust is coming back of anyways.

 

[Larry's Shee]

Is the stud stripped where the nut goes or are you using a bolt into the cylinder. Or is the stud spinning in the cly?

 

[pudvah]

I leak tested it after I got it back from Ken and it was air tight. I hear cycled re torqued the base and head bolts and have rode it once (besides around my yard to tune) it ran good but I did notice when I went to take exhaust off to do A arms the left side but was loose. When I went to put it back on I noticed the stud going into the cylinder is just spinning so I can't tighten it which causes a noticeable gap so I would think it's pretty bad leak. I do have a leak tester so I will do it again for the peace of mind since exhaust will be off but it did run good prior. I assumed it was cause of this but wanted to make sure. It's not real bad it comes back down in about 5-10 seconds but I shut it off immediately and will fix today.

 

[Bluesman]

It would be much easier to Heli-coil the cylinder with the motor pulled and on the bench.

 

[pudvah]

Motors already pulled and helicoil kit sitting next to it waiting for me to get home from work.

 

[Herpderplol]

Motors already pulled and helicoil kit sitting next to it waiting for me to get home from work.

tbh i wouldnt really trust a helicoil.

drill it out and tap it, then put a larger bolt in it. easier than doing helicoil IMO
so far we have done it on 3 out of the 4 blasters we have owned. 2 because they stripped, 1 for peace of mind

 

[Bluesman]

I have installed lots of helicoils in various applications and never had a failure. If done carefully and correctly, they are stronger than the original threads. The problem with just tapping to the next bigger size is that then the flange has to be drilled out and then when you sell the pipe, it's drilled out too big for the next guy and you have to drill out the flange on your new pipe, and on and on it goes.

 

[Fast6hand]

Just a thought. Is there enough room to put a through bolt and a nut on the backside? I'm not in front of my bike to confirm.

 

[pudvah]

No you can't get a nut in the back of it unfortunately. I would have done that instead.

 

[Blasturd]

I have installed lots of helicoils in various applications and never had a failure. If done carefully and correctly, they are stronger than the original threads. The problem with just tapping to the next bigger size is that then the flange has to be drilled out and then when you sell the pipe, it's drilled out too big for the next guy and you have to drill out the flange on your new pipe, and on and on it goes.

AGREED A helicoil is the best way to go, ive never had an issue with helicoils, aluminum threads wear out if there is a bolt being taken in and out repeatedly where the steel threads of the helicoil will not.

 

[jus_me]

On average how many times is someone going to remove the exhaust flange (once ported no need) ?? If the exhaust flange has a "slightly larger hole than whats the big deal? My exhaust flange has allot of play in it and it was new. I could easily go up a size maybe 2 and not have an issue with a larger stud going through.

Also as stated a bolt instead of a stud would also be a good option since some pipes can be a hassle to get in and out if and when needed. Tap to next size, get matching bolt, ream flange if even needed and be done. Although If planning on removing the ex flange/stud/bolt often than a helicoil might be best option. Don't matter the size. It would be less likely to cross thread or strip.

 

[Herpderplol]

On average how many times is someone going to remove the exhaust flange (once ported no need) ?? If the exhaust flange has a "slightly larger hole than whats the big deal? My exhaust flange has allot of play in it and it was new. I could easily go up a size maybe 2 and not have an issue with a larger stud going through.

Also as stated a bolt instead of a stud would also be a good option since some pipes can be a hassle to get in and out if and when needed. Tap to next size, get matching bolt, ream flange if even needed and be done. Although If planning on removing the ex flange/stud/bolt often than a helicoil might be best option. Don't matter the size. It would be less likely to cross thread or strip.

for my current FMF pipe the flange was welded on when i got it. I tapped the studs to a larger size (i had one strip)
I took a round file to the flange and that was all it took.