Need Advice on Welding Motorcycle Exhaust

[Honda guy]

I picked up a nice little Suzuki GZ 250 the other day, that needs some minor engine work. Tonight as I was disassembling it to pull the head, I found a broken exhaust pipe.

It doesn't look like it'll be that big of a deal to fix, but I wanted to get some input from some of you with welding experience. I have access to a wire welder and a gas welder and I can weld just good enough to get by. It's a pretty clean break and fits back together nice and tight. There are some small gaps that will have to be filled in (about 1/16 inch). That part of the exhaust is out of sight, underneath the engine, so the repair doesn't have to be pretty. It's a fairly lightweight exhaust and mounts securely, so it's not under a lot of stress.

Would brazing be the way to go?

 

[CJM8515]

Thin metal like that will not be an easy thing to weld as it will likely want to blow through as your going along. Im like you and can weld ok but not great and I would buy a new pipe or pay someone with a tig to do that.

 

[fnieto]

Mig weld it. Make sure to secure the muffler mount to the frame. More than likely the muffler mount came loose at some point and vibrated resulting in cracking. You may also consider a rubber grommet at the said mount for added vibration isolation. Many times the metal becomes fatigued and will crack again (at the toe of the bead) sometime after the repair.

 

[Screwdriver]

TIG will be tricky because you really ought to gas purge the inside plus you always get a lot of contamination which TIG does not like at all.

MIG would be much easier if you can get decent penetration without blowing through.

Brazing is the easiest and best option for a long lasting repair because the "weld" won't be brittle. There's a reason it cracked where it did, most likely fatigue and brass is particularly robust in those applications.

S.

 

[sailah]

Personally, and I used to build custom motorcycles as a hobby, I'd TIG weld that with an argon purge.

 

[Kiwi Canuck]

Honda Guy, the damaged pipe is available new for $183.00 from Parts Outlaw in Florida, so you may want to consider a new one.

Not sure what year your bike is but this one is for model year 2000 and they look all the same for all years.

Seems like a steal to me.


http://www.partsoutlaw.com/oemparts/a/suz/50d3295ef8700232d0b3cd40/muffler

Good luck,

David

 

[Bobcat753]

Looks like very poor quality stainless steel. I'd buy a new system as it looks like there will be more problems in the future with all the rust. A good stainless exhaust should never rust.

 

[Kiwi Canuck]

Looks like very poor quality stainless steel. I'd buy a new system as it looks like there will be more problems in the future with all the rust. A good stainless exhaust should never rust.

Bobcat, those pipes are chrome plated mild steel, not stainless.

Pretty standard on mass produced Japanese bikes of that price point and style.

 

[MoonRise]

Replace it.

The broken parts do seem to fit together well, but all those 'jagged' cracks going in all sorts of directions mean the part is (or was) under a lot more stress than you might think or realize. The crack(s) are jagged and also go up through the Y section of the pipe as well (Pic #2). Also seen in Pic#2 is where the crack went along the "toe" of the previous weld, so either the original weld there didn't fuse well to the pipe(s) (poor penetration) or the weld toe was undercut or some other geometry defect caused or contributed to the crack/break happening right there.

If trying to do a 'nice' weld repair (and not just a 'get me home' type of weld), I'd say you need to use TIG (with a backpurge) and you'll spend a lot of time and effort to grind away all the various crud (inside and outside) and also remove a bunch of the existing welds from the Y section. And you still might end up with crud and weld puddle contamination as you try and weld it, which means more grinding out of the contaminated welds and redoing it multiple times until you finally do (hopefully) get some 'decent' and 'clean' welds. Possible? Sure. Probably not a 5 minute welding job though. Not for a 'good' weld job anyway.

Replace the pipe and be done with it.

IMHO.

 

[sqznby]

It could be tig welded

 

[countryroad82]

I'd hit it with a mig. But mig is all I can weld with lol. Shouldn't be a hard fix.

 

[sberry]

Mig weld it. Nothing to lose.

 

[mike13u]

You dont need to backpurge that as it isnt stainless. MIG or TIG. But, you are going to rust over and look ugly unless you re-chrome or coat.

 

[Honda guy]

Thanks guys. Lots of great info.

I've decided to let a pro do the welding. A friend of a friend is an experienced welder and he'll do it for 20 or 30 bucks. I figure at that price, I'll give it a shot and if doesn't work out, then I'll just go with a used pipe.