Zongshen 200GY-A, rehab exhaust question

[tankme]

Originally Posted by Weldangrind

Also, your header has the dreaded catalytic converter in it, and you could scribe a reference line across the length, cut it open, gut it and weld it back up. You'd need to remove all of the rust first.

Is the red line where I should halve it?

Is there a preferred way to cut it? I can hacksaw it to lose the least amount of kerf, or chop saw it if it doesn't matter. I've never gutted a cc this small and it should prove interesting. I'll even post pics!

Thanks for the direction!
Jim

[Weldangrind]

I'd use a super thin cut-off disc in a 4-1/2" angle grinder and not worry about kerf loss. If you're skilled with a grinder, you could give it a lobotomy and cut the entire top half off, gut it and weld it up again. That would maintain your input and output pipe relationship, so you don't affect how it bolts up to the engine or the midpipe.

I don't think you could remove the honeycomb if you chopped the cat in half. If you cut it just before the transition on either side, I think you'd capture it. Make sense?

[Weldangrind]

As I think about it more, if you cut the rear half off, gutted it and welded it back up, nobody would see the surgery scars.

[recracer]

Just For FYI I think mine was empty from the factory . I check before I cut it ,a wire coat hanger . Maybe you will be lucky

[tankme]

recracer: Ok I will check to see, thanks, good point.

Weldandgrind: Hmm, I might be confused about orientation. I've lined up the pic again. Do you mean the black, or green lines? Heh Do you mean either the black or green lines?

Thanks! I'll be coming back to this as I'm elbow deep in the rear end and discovering more exciting things to fix. A post about Sprocket bolts coming up...

See you soon!
Jim

[Weldangrind]

I didn't explain myself well. I meant that you could cut the top off and leave the rest of the pipe intact. Hopefully the red lines give you an idea of what I mean.

[tankme]

Oh like a little access hatch. Roger that. Am all I'm expecting to see is honeycomb? Seems easy enough. Then the midpipe is the next part to start fabricating. I'll post pics of the task unfolding if I can remember.

I still haven't hangered it yet though, I've been un-taping all the hand taped parts of the harness looking for breaks or my chopped starter wire.

And I think I have discovered this bike was probably jumped off of something and the frame was broken and re-welded. I uncovered some welding wires poking out of a weld down in one of the frame joints and some welds on top of welds on the opposing joint. If I find cracks I'll need to attempt to patch them before I get all put back together. That's another topic again once I get that area of the bike clean enough to tell. Plus the swing arm makes contact with one of the passenger peg frames (which I'll prolly cut off anyway.)

Well there it is, I will gut/weld the cc and then ask questions about a mid-pipe and a PM about a muffler.

I'll be back!
Jim

[SpudRider]

Originally Posted by tankme

...I'll be back!

Jim

[tankme]

Heh



(at time of post I'm not sure how to make the video show up in the post. fixing)

[SpudRider]

I fixed it for you, Jim.

[tankme]

Woot Thanks!
Jim

[Weldangrind]

Originally Posted by tankme

Oh like a little access hatch.

More like a lobotomy. I would cut a little more than the top half off, so you can easily extract the offending honeycomb. It would still hold together well enough for you to stitch it back together, and you wouldn't mess with the heat shield fasteners.

[Weldangrind]

As a point of trivia, check out the honeycomb catalyst that was hiding in a China scooter muffler: http://www.chinariders.net/showthrea...ghlight=pastor