Well was riding home and found when I got there I lost 2 bolts from the head fell off!

What size are those bolts? How can I prevent that in the future..

08 Sportster 1200

 

I lost one last season from my rear CYL. I just went to the HD dealer and told them i needed a exhaust flang nut that goes on the CYL and they looked it up. Use loctite on them. Since I intalled the new pipes I have had to sug mine more then once and I need to check them again soon.

 

I wouldn't use loctite on those. The loctite will just melt due to the high temps and is the reason you have to keep snugging them up every once in a while. Throw a star or lock washer on there and you shouldn't have another issue.

 

Cool.. What size is that nut anyone know?

 

+1 - Loctite won't work at this location, the temps are too hot. Use a star washer and re-torque after 3 or 4 heat cycles.

The nuts are 5/16-24 (that's fine thread). Don't use Stainless Steel nuts here, you want plain old cadmium plated. Believe it or not, you actually want them to rust a bit onto the studs which keeps them from loosening up in the future. If you need to remove them at a later date, a penetrating oil like PB Blaster will free them up.

 

Awesome thanks for the help

 

Yep...what he said

 

LOL! I did not use loctite I forgaot, but looks like that was a good thing. Now that the pipes have been on the bike a few hundred miles the nuts stay tight.

 

I'm had the same problem more than 5 times with exhaust nuts on the rear cylinder only. Then I found after my last ride that the rear pipe cracked at the weld. Looking closer, the heat shield clamp and melted at the spot welds. Not the end yet. Rear pipe clamp broke near the case. This is clearly a heat/vibration issue with Harley Davidson Sportster.

 

The samething happened to me more than 5 times. Then the nuts came off, rear cylinder bolts stripped, rear exhaust pipe cracked at weld, clamp at case broke, exhaust shield melted at spot welds. This is a Harley Davidson Sportster Rear Cylinder Heat/Vibration Problem.