Topic: 77 Cb550 Exhaust studs? Solutions?

[Lostboy Steve]

I am a seasoned veteran of exhaust manifold studs (extraction, replacement, drilling, etc.) however I was wondering how everyone here goes about this. I have bad studs, half of them have pulled out of the head, the other half are just stripped. No idea how this happened. I was thinking of heli-coiling all of them and installing some grade 8, 6mm studs. Any other ideas. Next size maybe?

[Lostboy Steve]

Actually maybe these? http://www.ebay.com/itm/One-Motorcycle-Exhaust-Stud-Double-Ended-8mm-to-6mm-50mm-Long-/140634779069?pt=UK_Motorcycle_Parts&hash=item20be7c6dbd

[Lostboy Steve]

Ok let me ask you guys this, what size length would I be looking for if I decide to use allen bolts instead of studs?

[Stilltime]

The stock ones are M6x1.0 40mm long with about 12mm of equal threads on both ends.  You could try doing heli-coil and getting new OEM studs.  I just received four (needed one but ordered extras just in case) from a vendor online.  The part number is 90044-323-300, under $2 a piece.

You could use hex or Allen head bolts, but it isn't recommended.  With studs, the threads in the head aren't being tampered with each time the exhaust is pulled.  Whereas with bolts, every time you drop the exhaust you are wearing the threads and potentially doing more damage like that which has already been done on your bike from the PO.

One alternative I considered was ordering M6x1 316 SS studs, 40mm in length from McMaster and just using brass or bronze flange head nuts, but they are costy..

Hope that helps,

Chris C.

[MRieck]

Make sure you get the angle correct when you drill those stud holes

[Lostboy Steve]

Yes Sirs. I figure that the way its been going, tampering with the head is a 50/50 gamble. (half of my studs came out with the nuts) I assume it was all factory before I rebuilt it. At this point, and I am knocking the hell out of wood typing this, but hope fully by the next time I have to pull the bolts, nuts or studs, I wont mind redoing the whole thing. So for now, hopefully tomorrow I get some bolts.

[Bankerdanny]

If they came out with the nuts then they should go back in with no issues. Replacement studs aren't expensive.

[Muckinfuss]

Instead of Helicoil, try Fastenal for their EZ inserts.  Much better in this application.  The EZ insert will take far more stress in-line and laterally than the Helicoil will when in aluminum and there's no little break off laying in the bottom of your hole after you run the stud down and seat it.

[grcamna2]

Instead of Helicoil, try Fastenal for their EZ inserts.  Much better in this application.  The EZ insert will take far more stress in-line and laterally than the Helicoil will when in aluminum and there's no little break off laying in the bottom of your hole after you run the stud down and seat it.

I agree. I've used a product called "Timesert" which is an insert and locks into the original hole very well..,they've been serving the Powersports industry for a while.

[Lostboy Steve]

So here's what I did. I went to Home Depot and got some Allen cap 6mm x 30 bolts. Tapped the problem holes (only 2) to 7mm x 1.0 and installed the aforementioned heli coils. Then I tightened everything down with an Allen t handle wrench so as to not put too much torque into them seems good and looks nice.

[grcamna2]

They should be fine now. Do you feel you can put nice,even torque on all of them ? That's what I think matters...

[Lostboy Steve]

Yeah, they tightened down nicely and don't leak.