What happens if I don't fix broken exhaust bolts?

[antlese]

Hey guys,
I wanted to remove my exhaust so that I could replace my oil pan. Of course I snapped 1 bolt on pipe number 2 and 1 bolt on pipe number 3.

Not making much progress drilling out the bolts. If I just put the exhaust back on without fixing the broken bolts, will my bike run poorly due to air leakage around the middle pipes at the cylinder head?
Is it essential that I get this fixed?

Thanks
Antlese

[cowboyup3371]

The exhaust leak will cause you problems...fix it right

[chuck hahn]

That and the extra stress on just the one remaining bolt may snap that off too.

[azr]

To answer your question, yes your bike will run like crap, and worse you would lean it out and possibly damage your engine

[MiketheBike]

...and the other bolts will break after a while and you will have 4 to fix. There are several ways to remove these. Let us know what you are doing to get them out.

[antlese]

You guys are all telling me what I kinda expected. I have to get those broken bolts out.

I have the entire exhaust off. Also have the front fender off. I have been using left handed drill bits to try and drill into the bolts. The bolts are very hard and I'm making very very little progress. Both holes are slightly off centre, so if I increase bit size I will start drilling into the cylinder head threads.

I'm also spraying the broken bolts with PB Blaster.
There is not enough bolt protruding to get them with the vies grips.

I guess my options are to contine with the left handed drill bits. If I hit the aliminium threads then I will have to get the holes re threaded.

Or I could look for a new cylinder head...hopefully a last resort.

Antlese

[cowboyup3371]

Be very careful that you get dead on with that left hand thread bit; have you used heat on them as well as the PB Blaster? Is there at least enough room that you can weld on a nut?

[antlese]

Be very careful that you get dead on with that left hand thread bit; have you used heat on them as well as the PB Blaster? Is there at least enough room that you can weld on a nut?

To weld on a nut do I need some bolt sticking out? Mine are essentially flush with the cylinder head.

[cowboyup3371]

Yea you want some to be sticking out but I'm not an expert as I've been fortunate enough to not have to deal with it. I'm sure someone else can give better ideas

[chuck hahn]

Stick a bolt that did come out thru one of the exhaust flanges and measure the threads that stick out. Don't drill deeper than this as there are oil gallys that run directly behind the bolts in the head.

Make a mark on the bits and as you get close go real easy till you just feel the drill bit get thru the bolt...then STOP. If you drill into a gally your pretty well screwed.

[gs850cafe]

could make that one cyl run a bit more lean causeing a possible burnt valve...a annoying exhaust leak and maybe the other bolt with strip out

i drilled 2 of my spare head out..used a dremel cut bolt flush with head, center punched...used the drill bit i could push inside the good holes with damagin threads...drilled straigh as i could...ran a tap through it an its as good as new

[ashdricky]

I had a similar issue with the cyl head of a 650, and I have a solution that works quite well, Immediately stop trying all other methods ast they may remove too much material making it impossible to use this method.
1-tig weld (using a tig torch with sharp tungsten will make it easier to weld even if there is not much material left) a new bolt to what is left of the old one.
2-let it soak for a short bit in pb blaster as you have done.
3-heat the area around the bolt with a torch and slowly (Very slowly) tighten by a few degrees and then loosen by a few degrees any more and you will likely snap the bolt again, if you do then weld the new bolt back on and go again. most important thing is to be patient and dont go to extreme with either the heat or the torque you use to turn the bolt.
It eventually will come out, for me it took 2 hours of taking our time and being slow.

[Crage]

I had a similar issue with the cyl head of a 650, and I have a solution that works quite well, Immediately stop trying all other methods ast they may remove too much material making it impossible to use this method.
1-tig weld (using a tig torch with sharp tungsten will make it easier to weld even if there is not much material left) a new bolt to what is left of the old one.
2-let it soak for a short bit in pb blaster as you have done.
3-heat the area around the bolt with a torch and slowly (Very slowly) tighten by a few degrees and then loosen by a few degrees any more and you will likely snap the bolt again, if you do then weld the new bolt back on and go again. most important thing is to be patient and dont go to extreme with either the heat or the torque you use to turn the bolt.
It eventually will come out, for me it took 2 hours of taking our time and being slow.

How do you do this if the bolt is broken off flush w/ the head?

[antlese]

I checked out a few YouTube vids of guys welding nuts to broken bolts. Seems that the bolt can be flush and still get welded on ok. And the extreme heat generated helps break the bond on the threads.

I will be buying a welder soon. It's been a while since I treated myself to a cool tool. I've kinda always wanted a welder, so now I have a good excuse to get one.

Antlese

[ashdricky]

How do you do this if the bolt is broken off flush w/ the head?

I checked out a few YouTube vids of guys welding nuts to broken bolts. Seems that the bolt can be flush and still get welded on ok. And the extreme heat generated helps break the bond on the threads.

I will be buying a welder soon. It's been a while since I treated myself to a cool tool. I've kinda always wanted a welder, so now I have a good excuse to get one.

Antlese

yes you are right, you can weld a it even if the bolt is flush with the head, it may be that the steel bolt and the aluminum head have different melting points but im not sure, as far as welders go I have tig that I bought used and it is much more versatile than the mig that i was using, perfect for precision welding like you are talking about.