holes in expansion chamber.

Moisstink

Moisstink

New Member
I bought an expansion muffler a while back and have about a half hour riding on it. I was out today and noticed a decent amount of air is coming out of the weld from the underside of the expansion chamber closest to the engine. (if that makes sense). It was thirty bucks for the muffler so I am thinking I am SOL on them replacing. I will let you know how that goes.
Anyway, just wondering what effect something like a few 1/32nd holes along the weld seam will do and what kind of repair may be recommended if needed. It will drive me crazy knowing it is there so I will have to do something.

Thanks in advance for any responses!
Kevin
 
if they don't replace it, or even if they will but you dont want to wait, find a muffler shop or someone who welds to fix it. probably cost you a coupla bucks, or a six pack, or nothing.

a leak close to the engine can cause overheating and could be catastrophic to your engine.
 
bairdco said:
if they don't replace it, or even if they will but you dont want to wait, find a muffler shop or someone who welds to fix it. probably cost you a coupla bucks, or a six pack, or nothing.

a leak close to the engine can cause overheating and could be catastrophic to your engine.
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Heck.....I'll weld it for a six pack :D Just bring it on over, it's only a six hour drive ;)

dnut
 
You can always braze the holes shut with a mapp torch and some brazing rods from home depot or most hardware stores. If you got a propane torch you can just buy a cylinder of mapp gas and a few brazing rods for fairly cheap but a mapp torch and cylinder will cost you around $40, but with that you can braze most pieces with close to the same strength as welding. This is also a real easy way to add brackets and tabs to a frame if you don't have access to a welder or cant stop and take your project to someone to weld stuff up for you. Very useful tool to have in this hobby.. this will also let you make your own system or add or cut out header length to fine tune your pipe.
the last thing you need is an air leak close to your exhaust port, this can warp valves on a 4 stroke or melt a hole in a 2 stroke piston.
 
Just an update. I did not post the name of the vendor before because I wanted to give them a chance to do right about a damaged product. Well boygoesfast on ebay BLOWS!! I emailed those A holes four times. The email started off very tactful and lost that angle as I realized they would do nothing! I read past feedback for them and I guess if you are unlucky enough to receive a bad product they will do nothing to resolve it. They have done this with many customers from what I read in the feedback section. Oh well buyer beware with them. Anyway, I ended up picking up some jb weld due to the fact I am pretty tapped financially. I applied this yesterday and will take it out tomorrow for a test run (giving it a 24 hour plus cure time) . I do have a cnc alum muffler exhaust header which I am hoping will help with the heat of the muffler. The jb weld is rated to withstand heat of up to 500 degrees. I am wondering if I am in for a fail on this approach. Anyone know if a muffler heats up past 500 degrees a couple inches from engine with a header? Thanks for any info on this and watch out for the A holes at boygoesfast!!!
 
I would have used Muffler Putty rather than JB for a temp fix, you might be lucky, I have seen Muffler putty hang on for quite some time, It's cheap and you don't need to mix it.
 
I always keep a tube of this stuff, good for temporary fixs to exhaust manifold cracks, leaky flange gaskets, reusing old exhaust gaskets, ect. Hardens with heat.
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Moisstink said:
Just an update. I did not post the name of the vendor before because I wanted to give them a chance to do right about a damaged product. Well boygoesfast on ebay BLOWS!! I emailed those A holes four times. The email started off very tactful and lost that angle as I realized they would do nothing! I read past feedback for them and I guess if you are unlucky enough to receive a bad product they will do nothing to resolve it. They have done this with many customers from what I read in the feedback section. Oh well buyer beware with them. Anyway, I ended up picking up some jb weld due to the fact I am pretty tapped financially. I applied this yesterday and will take it out tomorrow for a test run (giving it a 24 hour plus cure time) . I do have a cnc alum muffler exhaust header which I am hoping will help with the heat of the muffler. The jb weld is rated to withstand heat of up to 500 degrees. I am wondering if I am in for a fail on this approach. Anyone know if a muffler heats up past 500 degrees a couple inches from engine with a header? Thanks for any info on this and watch out for the A holes at boygoesfast!!!
Click to expand...

Not sure if JB weld is the best stuff for these but my expansion chamber stays cool to the touch after the first bend on the pipe. Mine is made from a KTM 50 pipe that was cut up and rearranged to fit on the bike and surprisingly the heat is only from the exhaust flange to about 7 or 8 inches up the pipe, but it also starts to taper out right at the flange so it really doesn't get that hot until it's been run really hard.

You can try the JB weld but be sure teh surface is really clean before applying it and give it plenty of time to set up, over night is best. It should hold as long as there's not a lot of vibration in the pipe and as long as the heat is elsewhere, apply it in thin layers also to prevent cracking.

The muffler putty might be a better idea depending on how much heat is in the area, but if it cracks from vibration you may need to resort to some Permatex Ultra Copper and let it cure overnight as well, this stuff can withstand at least 500 degrees and staye flexible. Either way, and no matter what you use, be sure the surface is Clean and free of all oils and grease, a can of carb and choke spray or brake cleaner is great at degreasing.

Another method for repairing holes in a pipe is to wrap the effected area with a single layer of thin steel wire like safety wire and then solder the wire to the pipe with silver solder, you'll need a propane torch to get it hot enough tho. This also works with brazing, but you'll need a hotter flame like mapp gas to make it work.
 
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Let us know how it works out for your repair... ive seen the stuff at the auto parts stores but not really paid much attention to it...
 
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