Loose exhaust flange

[Anonymous]

Hi Guys,
I just found out that one of my exhaust flanges is loose due to a missing exhaust bolt that should go into the cylinder head. How big of a deal is this? Do I need to have a good seal for proper back pressure?

The symptoms I currently have are low power from 3-5000 RPM and a lot of noise that I earlier believed to be loose valves but it isn't that as I adjusted them. The low power could be caused by the outdoor temp of -15C but I am not sure.

I'm too busy to mess with this bike so my plan is to get a big C-clamp or a pair of vice grips in order to lock down the flange as well as I can. Will this be good enough for a few hundred kilometers over 3 weeks?

Thanks, Steve

[Clone]

Getting a big c-clamp seems to me like messing with it. Just stick a bolt in the hole with some Loctite and call'er quits.

[Anonymous]

I agree with Clone. Aside from the fact that I can't imagine how a c-clamp or vise grips would fit or work, the question becomes "why?". I think you will spend a lot more time trying to figure out an alternative metod of fastening the pipe back down rather than just putting another bolt in.

As for the consequenses fo leaving it as it is now. Short term, probably nothing other than some noise. Long term, the hot exhaust gasses could eat away at the mating surfaces and cause pitting. That's a 'maybe' scenario - wouldn't bet my life on it, but I wouldn't leave it alone.

Steve

[G man]

Check the threads for damage. Don't ask me how, but it happened to me once. I owned the bike for 2 years with no problems when it suddenly developed an exhaust leak. The header collar on cylinder 2 was cockeyed and missing one bolt. I thought the bolt had vibrated loose somehow and dropped off. Got a new one at the dealer and when I tried to install it I found the threads on the hole were completely gone.

If stripped out, cylinders 1 and 4 are not a big deal. You can easily helicoil them. 2 and 3 can be a real pain if the frame downtubes are in the way.

Try to fix it right as soon as you can. Many "limp along" repairs I have seen ended up causing more damage in the end.

[Billy Ricks]

If the threads are shot either heli-coil it as has been mentioned or drill and tap to the next thread size. You could even go to an S.A.E. size to keep from having to use too large of a bolt.

[Anonymous]

I just had a good look at the situation and have found that the head of the bolt popped off. My next step is to go to Canadian Tire and pick up a 10" clamp as it is exam time and I'm not going to spend an afternoon fixing the bike.

When I get around to fixing it I'm hoping that the bolt is loose enough that I don't have to drill it. If it needs to be drilled I'll have to pull the head because I don't want to jack around and do a poor job of it like the last guy did. :?

Steve

[moto_dan]

Sure hope that 10" clamp doesn't fall off when riding and cause other problems like crashing your brains out. 8O

[Anonymous]

dan:
No problemo, I'll have lots of safety wire on it. As crazy as some of my plans appear I'm very thorough in disaster planning.

Steve

[Anonymous]

When you do take the head off and determine if the threads are stripped or not you can always go up one thread size. The stock ones are 8x1.25mm retap out to 9x1.25mm good luck

[Anonymous]

I just had a good look at the situation and have found that the head of the bolt popped off. My next step is to go to Canadian Tire and pick up a 10" clamp as it is exam time and I'm not going to spend an afternoon fixing the bike.

When I get around to fixing it I'm hoping that the bolt is loose enough that I don't have to drill it. If it needs to be drilled I'll have to pull the head because I don't want to jack around and do a poor job of it like the last guy did. :?

Steve

With the right tools it would take you less time to fix it right than it would for you to post a couple of times on here. Just an observation.