skarpenz Posted February 10, 2010 Share Posted February 10, 2010 Hey guys, I have been buying up and restoring/selling vintage Jap bikes for a little bit now and I need to know exactly what I'm working with here. I picked up a 1979 Yamaha XS400 roller (complete frame/engine/wheels/brakes) without a tank or seat/seat pan. I'm thinking its a XS400 Special which is sort of a bummer because I want to build up a plain XS400 for a sportier bike. I can't complain though, I scored the whole thing for $60. I disassembled the bike before ID'ing it exactly but here is a picture of the bare frame. My main concern here is this: If I source the seat pan and tank from a regular XS400 will I have to heavily modify the frame to fit those pieces? I do NOT like the look of the Special, it just isn't my style. If anyone could give some insight on this it would be much appreciated. Hell, if I could just see a detailed picture of an XS400 with the seat and tank off I could make the comparison myself. Also, if anyone could list the specific differences between XS400's and the Specials then that would be great too. There does not seem to be much in the way of literature on these bikes. Thanks for any help guys! Pics: Some pics of my other projects; CB550fourK ($65) and GS1100EZ (Dad's): Link to comment Share on other sites More sharing options...
BRB Posted February 11, 2010 Share Posted February 11, 2010 2L0 is a 1978 XS400E. The frame looks ditto to my 360 frame but you will definitely need a few measurements if you plan on using the squarish tank. Link to comment Share on other sites More sharing options...
skarpenz Posted February 11, 2010 Author Share Posted February 11, 2010 2L0 is a 1978 XS400E. The frame looks ditto to my 360 frame but you will definitely need a few measurements if you plan on using the squarish tank. Any idea what sort of measurements and reference points? Thanks for clearing up the year and whatnot. Link to comment Share on other sites More sharing options...
BRB Posted February 11, 2010 Share Posted February 11, 2010 Any idea what sort of measurements and reference points? Thanks for clearing up the year and whatnot. I could give you a few measurements off my bike to see if yours could except the same tank as mine. I will post tomorrow some time. Link to comment Share on other sites More sharing options...
Speedshop Posted February 11, 2010 Share Posted February 11, 2010 The way to tell the XS400 models apart is the SE models had rubber mounted engines, with front mount that has larger holes to accomodate rubber bushes. The older 'roadster' models had solid engine mounts. Both are interchangeable but you'll need all the mounts for the FRAME you are using. Link to comment Share on other sites More sharing options...
skarpenz Posted February 11, 2010 Author Share Posted February 11, 2010 The way to tell the XS400 models apart is the SE models had rubber mounted engines, with front mount that has larger holes to accomodate rubber bushes. The older 'roadster' models had solid engine mounts. Both are interchangeable but you'll need all the mounts for the FRAME you are using. Okay, so I have all the solid engine mounts from this bike since I dismantled it myself (no rubber bushings). The only thing I am concerned with is the fitting of the long skinny seat and the square tank. Link to comment Share on other sites More sharing options...
skarpenz Posted February 11, 2010 Author Share Posted February 11, 2010 I could give you a few measurements off my bike to see if yours could except the same tank as mine. I will post tomorrow some time. Thanks very much. Link to comment Share on other sites More sharing options...
BRB Posted February 11, 2010 Share Posted February 11, 2010 I modified photo's of my frame to show the measurements. I used a 1" wide carpenters tape taking the measurements from the top of the blade as you face it. All measurements taken from left side of frame. Link to comment Share on other sites More sharing options...
skarpenz Posted February 11, 2010 Author Share Posted February 11, 2010 I modified photo's of my frame to show the measurements. I used a 1" wide carpenters tape taking the measurements from the top of the blade as you face it. All measurements taken from left side of frame. All my measurements jive with what you've shown me. All but one. That upward protruding hollow peg on the flat sheet metal cross brace that you used for a reference point. That brace on my bike is further back and the peg sweeps back at a ~45* angle. Is this going to be a big deal? My bike had nothing on the top of it when I got it so I'm not 100% sure what purpose that brace serves in my tank/seat dilemma. Thanks again for the help. Any input is welcome right now. I'd really like to get the frame to the powder coat shop tomorrow but if I need to cut and weld something then I will hold off. Link to comment Share on other sites More sharing options...
BRB Posted February 11, 2010 Share Posted February 11, 2010 All my measurements jive with what you've shown me. All but one. That upward protruding hollow peg on the flat sheet metal cross brace that you used for a reference point. That brace on my bike is further back and the peg sweeps back at a ~45* angle. Is this going to be a big deal? My bike had nothing on the top of it when I got it so I'm not 100% sure what purpose that brace serves in my tank/seat dilemma. Thanks again for the help. Any input is welcome right now. I'd really like to get the frame to the powder coat shop tomorrow but if I need to cut and weld something then I will hold off. The top tube is welded into a cross brace. It is not flat but round tube (pipe). I think you measured back to far. Link to comment Share on other sites More sharing options...
skarpenz Posted February 11, 2010 Author Share Posted February 11, 2010 The top tube is welded into a cross brace. It is not flat but round tube (pipe). I think you measured back to far. Oh no I measured from where you are talking about. I mean the rear reference point in the first pic. That upward pointing tube on the flat brace. Look in the pics I posted, that thing sticks out at a rearward angle instead of straight up like yours. Link to comment Share on other sites More sharing options...
skarpenz Posted February 11, 2010 Author Share Posted February 11, 2010 The top tube is welded into a cross brace. It is not flat but round tube (pipe). I think you measured back to far. I just realized that cylindrical peg is the tank mounting point. That sucks because mine is WAY different. Looks like I'll have to do some fabbing on this frame after all. Link to comment Share on other sites More sharing options...
BRB Posted February 11, 2010 Share Posted February 11, 2010 I just realized that cylindrical peg is the tank mounting point. That sucks because mine is WAY different. Looks like I'll have to do some fabbing on this frame after all. Yes I see what you mean. Mine is slightly bent forward from vertical and your mount is angled back to except the Special tank. It shouldn't be that hard to fix, you might be able to cut flat plate and bend mount to except tank and weld. You might want to fab after you find the tank though. I found a decent '77 XS400 tank on eBay for about $40 shipped to use for my cafe seat cowl. Link to comment Share on other sites More sharing options...
Moderator drewpy Posted February 11, 2010 Moderator Share Posted February 11, 2010 I just realized that cylindrical peg is the tank mounting point. That sucks because mine is WAY different. Looks like I'll have to do some fabbing on this frame after all. might get an aircooled RD to fit ( ask Merv) and I'm sure that the later german spec ones had that setup, but I can't seem to find it yet! Link to comment Share on other sites More sharing options...
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