Newbie welding an exhaust as first project

[kennethshaw]

Hi guys,

I'm new to the board and new to welding. I picked up a Hobart Mig 120 V welder to do some modifications on a cb175 cafe racer. I am looking to try to weld exhaust tips to the existing headers. I also need to add baffles. I was wondering what the best technique is for getting a good weld. Also, do I weld the baffles in first?

These are the baffles that I bought and they slide into the exhaust tips.

http://www.jcwhitney.com/8-internal-mini-mufflers/p2006472.jcwx?filterid=c14658d8971y1973j1

Any help would be really really appreciated.

Ken

[Blacksmith]

I'd use gas shielded solid wire (MIG) and tack or skip welding to avoid burning out the glass packing (any more than it already is based on the picture in your link) Probbaly weld the baffles in first since as I understand your project it'll be easier to position the tips for easy welding. Once you attach the pipes I imagine the assembly will be more cumbersome to rotate and hold steady.

[urch55]

A lot of bikes I worked on the baffles were bolted/screwed in. The second to last one I worked on was a Harley and I reworked/adjusted the factory baffles and they were bolted in; Made my job less aggravating.
But if you insist on welding them in just tack weld them in, this way if you have to adjust the back pressure/resistance it will make your life easier.

[Hotfoot]

I'd trmporarily install them with a couple pop rivets, so you can see how the bike runs with them in there. I've used a lot of diferent types/styles over the years, and most of them "stuffed up" the engine at higher RPMs.

The preferred method has always been to bolt them in (weld a nut to the muffler, and the bolt passes through the pipe), but if youwant to weld them , the trial with the pop rivets will tell if you made a good choice on the baffles. If you are using the fiberglass packed ones, you want to be sure to install them so the packing acn be replaced as it blows out (which it will!)

Most baffles can be cut shorter to tune the flow somewhat. Mess with it a bit to get it 'just right'.