Exhaust/Fuel HELP!

[VintageWWII]

So i'm a bit confused on what I should do next. I was riding on the highway when i heard my bike get extremely loud, at first i was like wow it must be the surrounding walls making it sound louder but when i got off, the loud noise was still there, and I look down and my 24" muffler is gone and whats left is a my header section. Now i rode about a couple blocks and actually found it and put it back on. The sound was a bit different, don't really like how it sounded but by the end of night. It became extremely loud, the engine was a bit smoking, very very hot, I can feel it and a shot load of backfire. Now i don't know what to do next? Re jet? Change exhaust? The muffler got a bit damaged and here are some pictures of it, help me out!

[Leland1]

Hmm.... Have you put a sync tool to the carbs? the smoke makes me think running rich and the running hot could be its running rich enough to dump gas into the oil like its not firing at the right position of the piston. Had that problem with my virago until
i synced the carbs

[VintageWWII]

Hmm.... Have you put a sync tool to the carbs? the smoke makes me think running rich and the running hot could be its running rich enough to dump gas into the oil like its not firing at the right position of the piston. Had that problem with my virago until
i synced the carbs

I don't but that's what I was thinking, I was thinking it went out of sync because I was riding like a couple blocks (fell off right before my job) pretty much without the muffler.

[UncleMike]

I don't but that's what I was thinking, I was thinking it went out of sync because I was riding like a couple blocks (fell off right before my job) pretty much without the muffler.

That wouldn't cause your carbs to go out of sync.

[VintageWWII]

That wouldn't cause your carbs to go out of sync.

Hmmm, then what could it be? Everything was perfect, this happened, now i'm running really hot, really loud, and backfiring out the ass. I hope it's just as simple as a muffler swap anyhow? Any more input?

[UncleMike]

Hmmm, then what could it be? Everything was perfect, this happened, now i'm running really hot, really loud, and backfiring out the ass. I hope it's just as simple as a muffler swap anyhow? Any more input?

You have an exhaust leak, which means you have no back pressure. I don't know what condition your carbs/valves were in beforehand, so it's hard to comment. But we know that you have an exhaust leak that needs to be addressed. If it was a muffler with a slip-on, there's a chance it was a cheap system to begin with and was rotten internally already.

[VintageWWII]

You have an exhaust leak, which means you have no back pressure. I don't know what condition your carbs/valves were in beforehand, so it's hard to comment. But we know that you have an exhaust leak that needs to be addressed. If it was a muffler with a slip-on, there's a chance it was a cheap system to begin with and was rotten internally already.

I believe it was a Mac 4 into 1, with a slip on and a clamp used to hold it together. I just hope it's a simple muffler swap.

[UncleMike]

I believe it was a Mac 4 into 1, with a slip on and a clamp used to hold it together. I just hope it's a simple muffler swap.

Most likely, although Macs are notorious for rusting out.

[VintageWWII]

Most likely, although Macs are notorious for rusting out.

Yeah man but I have a '79 GS 550, i have been looking for a flat black full exhaust but can't find anything good. All the good ones come for the later 5's or 750's. Any other good exhaust co's you can recommend? V&H?

[UncleMike]

Yeah man but I have a '79 GS 550, i have been looking for a flat black full exhaust but can't find anything good. All the good ones come for the later 5's or 750's. Any other good exhaust co's you can recommend? V&H?

I always go stock. I think your options are limited, but I'm sure some of the 550 guys will be around to chime in.

[VintageWWII]

I always go stock. I think your options are limited, but I'm sure some of the 550 guys will be around to chime in.

Yeah but I hate the stock look, I'm looking for something in the black department. I do have the stock exhaust, if i swap out my stock exhaust for my current one for the time being do I have to re-jet or sync anything or is it plug and play?

[UncleMike]

Yeah but I hate the stock look, I'm looking for something in the black department. I do have the stock exhaust, if i swap out my stock exhaust for my current one for the time being do I have to re-jet or sync anything or is it plug and play?

Is everything else stock? Have you cleaned/rebuilt your carbs? Checked your valves? Eliminated air leaks?

[VintageWWII]

Carbs rebuilt and cleaned, valves and no leaks. Everything was fine up until this mishap.

[UncleMike]

Carbs rebuilt and cleaned, valves and no leaks. Everything was fine up until this mishap.

Yup, just put on the stock exhaust and revel in your new-found mid-range power!

[VintageWWII]

Yup, just put on the stock exhaust and revel in your new-found mid-range power!

Haha thanks man! You've been quite the help.