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View Full Version : Who has CRF/XR50 exhaust on an ATC70?



Blown 331
04-14-2012, 03:06 PM
I'd like to give one of my ATC70s a little more volume without spending a bunch of money. A friend of mine has the Cobra pipe which actually sounds great, great power too. Sterdy Products has a system that look EXCELLENT to me but more than I want to spend.
I searched and couldn't find a whole lot on the subject but did see it has been done. The thread I found was 6 years old so I'm sure things have changed a bunch since then. I did find one other thread but I lost it, it wasn't real helpful anyway.
http://www.3wheelerworld.com/showthread.php/58052-CRF-50-Exhaust-on-ATC-70-(pics)?highlight=70%20exhaust

So who can enlighten me on this subject? The do's and don'ts. My goal right now is just sound. I'm planning on an 88cc kit down the road. I've got an 88cc kit on one of my XL70s and it made a huge differnce. Off subject but I've also got an SL70 that I bored the cased out on for a 95cc kit but that isnt finished yet.

And is it ok to just throw the cheapes pipe on there? Something like this. http://www.ebay.com/itm/EXHAUST-PIPE-MUFFLER-HONDA-XR50-CRF50-DIRT-PIT-BIKE-/150773986598?pt=Motorcycles_Parts_Accessories&hash=item231ad47526&vxp=mtr
I'm not a real fan of chrome exhaust though. I'd rather have stainless or painted if possible but I guess you can't be picky and cheap. :D

I'm looking forward to suggestions and input.

Here's 2 of mine.

http://i1041.photobucket.com/albums/b411/Blown_331/atc702.jpg
Thanks.

murfman
04-14-2012, 11:10 PM
I am looking for the same answers. I was thinking about the same E-bay pipe, and wrapping it with header wrap to keep from cooking my johnson. Looks to me like you can tweek the bends with a conduit hickey to make it fit.

sledcrazyinCT
04-15-2012, 09:48 AM
I wish the folks selling these parts on ebay would give dimensions of the flange and pipe ID so you can match it up to other applications. I am sick of not riding my 110 cus the exhaust is shot but I do not want to buy a pipe cheap, wait a week or two for it to arrive only to see it won't work. I can tweak and bend the pipe no problem but if the flange or the pipe is not right size to fit in the head then time and $$ wasted

If someone would provide a good drawing or print of header pipes with specs I work with a hydraulic company that has a CNC tube bender that goes up to inch and a half pipe and the stuff they bend up for dozers and backhoes turn out perfect. I want them to make me a pipe out of stainless I bring to them they would do it for a fair price if I provide the materials

trizilla
04-15-2012, 09:53 AM
i have used this pipe with success. it requires a little tweaking at the upper bend and i had to cut about 3 inches off the end of the header but it works great and sounds good too.
http://www.ebay.com/itm/MUFFLER-EXHAUST-PIPE-HONDA-XR50-CRF50-XR-CRF-50-Flat-/360411067236?pt=Motorcycles_Parts_Accessories&vxp=mtr&hash=item53ea2c7364#ht_7855wt_1114

atc350xer
04-15-2012, 04:15 PM
Yeah, what most of the pics don't show you is the upwards bend near the silencer. They are made for motorcycles, after all. I bought a stainless one last year, and I thought the same thing, just bend it down, but the muffler shop guy said it wouldn't bend nice, it would squish. I thought of maybe cutting and sectioning it, but I just shelved it and custom made one... a pit bike header mated to a Supertrapp... sounds awesome! To answer the original question, the pit bike motors are based on the Honda 70 motor, so the header should mate up, no problem. The 90/110 has a different bend at the exhaust port, so they would require some tweaking.

Thorpe
04-15-2012, 05:08 PM
I have a BBR pipe I customized for my 83... Its noisy, but fits perfect, clears all the plastic, and no worries about cooking your johnson...