Bending a muffler

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geoldr

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Jun 19, 2011
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California
Hi, I need to bend my muffler about an inch, so the pedal crank won't hit it. The only tools I have is a vice, and two clamps. How can I bend it? This is the last step for me to get my motor running (hopefully)
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Heat isn't necessary. If you have the vice you're half way there. Clamp the exhaust flange in the vice and bend away. Be careful and don't over do it. Go slow and you'll get there. Sometimes all you need to do is open up the holes in the flange where the pipe attaches to the cylinder, some call it "wallowing out the holes' to a larger size and that will allow you to angle the pipe enough to clear whatever obstructions.
If you want to protect a chrome surface just clamp the flange between blocks of hard wood instead of the vice jaws.
Some have devised a way of bending the pipe by bolting the exhaust flange to an immovable object by using the mounting bolt holes and bending the pipe that way instead of clamping in a vice. Do what works for you. Good luck.
Tom
 

Al.Fisherman

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Sep 9, 2009
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Calera, Alabama
Hi, I need to bend my muffler about an inch, so the pedal crank won't hit it. The only tools I have is a vice, and two clamps. How can I bend it? This is the last step for me to get my motor running (hopefully)
Like in the movie "Taken".....goood luck. I wouldn't think about bending without heat. How did you put the bike together with a vise and two clamps (your only tools)?. Go get a torch, heat till cherry red where you want the bend (while it in the vise) and put a pipe or the like in the hole, and bend it slowly. There are other ways like 2 door says.

One like this..can be gotten cheaper. All you really need is the tank and tip.
http://www.google.com/products/cata...=X&ei=qAAATrKKG8iztwfEyq2mDg&ved=0CKABEPMCMAU

http://www.harborfreight.com/electric-start-propane-torch-91061.html Tank not included.
 
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geoldr

New Member
Jun 19, 2011
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California
I think I will have to buy a torch. Al.Fisherman in your sig there is a link to a cheap torch, I live right by that store, looks like I will have to go check it out tomorrow. And what I mean by my only tools, I meant my only tools for bending the muffler. I have mostly everything else
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Hey sorry I am still new to this, what do you mean oval the two mounting holes?
Venice didn't use proper machinest terminology. We call it 'wallowing out' the holes...
Just make them bigger! If a 1/4" drill will go through the holes, try a 5/16". The bigger the holes in the flange the more you'll be able to reposition the pipe/muffler. Not always but sometimes just enlargening the flange mounting holes will allow enough movement to get the clearance you need. Just use common sense. Don't go too big.
Tom
 

geoldr

New Member
Jun 19, 2011
260
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California
Venice didn't use proper machinest terminology. We call it 'wallowing out' the holes...
Just make them bigger! If a 1/4" drill will go through the holes, try a 5/16". The bigger the holes in the flange the more you'll be able to reposition the pipe/muffler. Not always but sometimes just enlargening the flange mounting holes will allow enough movement to get the clearance you need. Just use common sense. Don't go too big.
Tom
Oh ok that's what I thought he meant. This method will still work using the stock gasket right?
 

2door

Moderator
Staff member
Sep 15, 2008
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Littleton, Colorado
Yes, but we recommend replacing the kit supplied gaskets with a good quality automotive exhaust gasket material. It will last much longer.
You'll want to make sure you have a good flat gasket surface on the exhaust pipe flange. Use sandpaper or a file and rough up the surface and make sure it is flat/flush to the cylinder for the best seal. Don't overtighten the fasteners. Good luck.
Tom
 

geoldr

New Member
Jun 19, 2011
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California
On my muffler, I think its called the flange? The part that connects to the motor, is not straight. I am not sure what to do, what's the best way of straightening it out
 

Al.Fisherman

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Sep 9, 2009
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Calera, Alabama
I think I will have to buy a torch. Al.Fisherman in your sig there is a link to a cheap torch, I live right by that store, looks like I will have to go check it out tomorrow. And what I mean by my only tools, I meant my only tools for bending the muffler. I have mostly everything else

I was poking a little fun at you. I know that you can't install these engines, with a vise and clamps.. :>) Some enlarge the holes in the flange... but what if... you enlarge the hole and it is not enough and you decide that you need to still bend the pipe...do you want to install the muffler with enlarged holes in the flange...I wouldn't want to. What ever works for you will be fine, at least you have choices.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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Los Angeles, CA.
Venice didn't use proper machinest terminology. We call it 'wallowing out' the holes...
Just make them bigger! If a 1/4" drill will go through the holes, try a 5/16". The bigger the holes in the flange the more you'll be able to reposition the pipe/muffler. Not always but sometimes just enlargening the flange mounting holes will allow enough movement to get the clearance you need. Just use common sense. Don't go too big.
Tom

No, I actually meant to say "oval the holes". I file just the top of one hole & the bottom of the other so the pipe can be turned without making the holes too big. ;)
 

Al.Fisherman

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Sep 9, 2009
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Calera, Alabama
No, I actually meant to say "oval the holes". I file just the top of one hole & the bottom of the other so the pipe can be turned without making the holes too big. ;)
I agree, but how much filing to oval the holes are needed. If we were at the bike then we could determine just how much was needed. I have bent the pipe (with heat) at two different spots, to make room for the bike crank. I have also had to bend the crank on certain builds. And some of both.
 

Cabinfever1977

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Mar 23, 2009
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Upstate,NY
I had to and was able to bend the muffler pipe without a torch, i used a giant cement block/wall that had a rebar loop at the top(thats for bulldosers can pick them up with a hook and chain) so i wedged the muffler pipe under the rebar loop and put my weight into it and hung on it( i weigh around 120lbs or so) i bent the pipe slowly a little at a time and kept trying it to see if it fit on the engine just the way i needed it to.
 

geoldr

New Member
Jun 19, 2011
260
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California
Hey guys, in bought a torch for 11 bucks at home depot, and was able to bend it without many problems. Although the vise also bent the pipe (but not the muffler) inward a little. I guess I should have used sand or something.

It will still be ok right?