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Old 09-26-2008, 11:58 AM
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2door 2door is offline
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Location: Littleton, Colorado
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Default re: Motorized Bicycle Take a Tip...Leave a Tip

Oily exhaust and brakes don't mix. I posted a question about this elsewhere in this forum but didn't get a reply. The mufflers on these little 2 cycles are all about the same so I know I'm not the only one to experience oil from the exhaust getting on the rear rim and reducing the friction of the brake pads. Even after break-in when we reduce the oil percentage they're still 2 cycle motors and will have oil in the exhaust. Originally I had considered making an extension to the exhaust stinger on the outlet of my muffler that would run along the chain stay and exit well to the rear to get the exhaust away from the rim but I solved the problem with a simpler solution that only took minutes to do.
I used a copper plumbing fitting correctly refered to as a 45 degree street L. I cut two slits in the unswedged end of the fitting, much like your carburator has on the manifold side, and used a standard stainless steel screw type clamp to secure the fitting to my muffler. Before tightening the clamp I turned the fitting so the exhaust was routed out and away from the rear rim. Before this simple mod I was cleaning my rim and brake pads after every ride with brake-wash (solvent) but now after riding my bike a week the rim is dry and oil free. The cost was nothing because I had the parts laying around but if you buy them the cost should be under $2.00. The attached pictures show the process you'll need to do. I'm sure the old hands here will find this very elementry but to newbies, like me, it might be something that could save them some grief. Plus it's a sure safety issue.
For those unfamiliar with plumbing fittings the first photo is a comparison between a street L and a standard L. One end of a street L is not swedged.
The second pic is of cutting the slit in the unswedged end after measuring the length of your exhaust outlet pipe. Don't make the slit deeper than the pipe is long or you'll have a leak. I used a Dremel tool with a cutoff wheel but a hacksaw will work too. The slit ideally should have a slight taper to it. Wider at the open end so it can be compressed to fit the outside diameter of the exhaust pipe of your muffler.
The remaining photos show the parts and the final installation.
Good luck and enjoy your dry brakes.
Attached Images
File Type: jpg Exhaust, 1.JPG (74.5 KB, 213 views)
File Type: jpg Exhaust, 2.JPG (80.2 KB, 220 views)
File Type: jpg Exhaust, 3.JPG (70.5 KB, 201 views)
File Type: jpg Exhaust, 4.JPG (74.0 KB, 224 views)
File Type: jpg Exhaust, 6.JPG (87.2 KB, 475 views)
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Last edited by 2door; 09-26-2008 at 12:04 PM.
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