XSMX Exhaust

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I've been lurking and sometimes posting for awhile now. Seeing the headers that have been posted lately made me decide to post a couple pics of a sportsman open twin race bike that I am slowly building. I am in no real hurry since I am in a long slow recovery from a broken back.This is a '71 Yamaha XS650 that I have narrowed the rear section of the frame to fit the mx seat and fender. The exhaust is 1.5" 304L stainless. In the pictire is a megaphone that I made and have since decided not to use. I nade the exhaust a 2:1 mainly to have something different. The picture with the yellow tank shows the first exhaust I made, using a different frame that was newer and had the frame tubes placed differently, so the exhaust didn't fit right. Attached ImagesRichard TerryMarine engineer.............  C'mon retirement!
Reply:Cool BikeLooks good to me.Mack
Reply:I think there´s  a lot of engineering that should be taken into account when building an exhaust...Did you design it? or just make it fit?My Babies: HF Drill pressHF Pipe Bender3   4.5" Black and Decker angle grindersLincoln Electric PROMIG 175that´s it!
Reply:It is designed. I have built many exhaust systems for bikes, including 2 strokes. I kept the primary tubes smaller in diameter to match the carbs I am using, making jetting easier. Most people go too large and really hurt the power down low. The primaries aren't equal in length, the right side tube is 2.5" longer, but this isn't a high rpm engine.Last edited by Yamahammer; 05-13-2008 at 04:27 PM.Reason: misspellingRichard TerryMarine engineer.............  C'mon retirement!
Reply:Originally Posted by YamahammerIt is designed. I have built many exhaust systems for bikes, including 2 strokes. I kept the primary tubes smaller in diameter to match the carbs I am using, making jetting easier. Most people go too large and really hurt the power down low. The primaries aren't equal in length, the right side tube is 2.5" longer, but this isn't a high rpm engine.
Reply:Eric Gorr has a great book about all 2 stroke tuning.There is some good info online such as this one: http://www.motorcycle.com/how-to/how...care-3423.htmlI lot of what I have done has been trial and error, such as stinger length.Richard TerryMarine engineer.............  C'mon retirement!
Reply:Originally Posted by YamahammerIt is designed. I have built many exhaust systems for bikes, including 2 strokes. .
Reply:It'll be a while before I get it running. I leave tomorrow to go back to sea for 2 months.When I get home, I have to swap out engines. The one in it only has a crank and tranny. Everything else was stripped out so I could use it as a mockup while I was overhauling one of my good engines.I think it will be a blast to ride.Richard TerryMarine engineer.............  C'mon retirement!
Reply:Wow, very cool bike. Definatley looks like a blast to ride..
Reply:Originally Posted by YamahammerEric Gorr has a great book about all 2 stroke tuning.There is some good info online such as this one: http://www.motorcycle.com/how-to/how...care-3423.htmlI lot of what I have done has been trial and error, such as stinger length.
Reply:Don't you just love those old bikes??Exhaust just in the right place for severe leg burns when you crash the wrong way..Don't ask....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by zapsterDon't you just love those old bikes??Exhaust just in the right place for severe leg burns when you crash the wrong way..Don't ask....zap!