bornloser
New Member
Hi all!
Im from the good old PNW, just north of vancouver WA. Ive got two bikes currently, a cb360 thats torn down into boxes and the motors getting a good going through on the bench right now and then an 81 xs400 which is the subject of this experiment!
Ive lurked and lurked and lurked forever and done plenty to my bikes in that time but I never thought any of it was really worthy of its own thread on here! Conversions for the XS400 seem few and far between, or well any documenting for them at least.
So the general plan is to take a basically stock running xs400 and turn it into a dual sport dirt tracker! There have been minor aesthetic changes to the bike (dirt bars, mirrors, turn signals, seat) and ive only really delved into the engine to get her running (cleaned and rough synced carbs, shims on the needles, new air filters, valve adjustment).
SO a little background on this idea! I live pretty far out side the city where forest access roads are much closer (and really much more fun) than the highway. I dont have a dirtbike and didnt really feel like buying one right now. I figured I would just turn my xs400 thats just sitting around not running right into a nice little dirt-to-street bike. The plan is to remove the existing swingarm, rear wheel and battery box from the bike. Once the frames cleaned up I can start to mock up the YZ125 swingarm and figure out where the monoshock mount needs to be on the xs400's frame to give good travel and avoid binding. Probably going to end up having the mount just below the gas tanks mounting bolt, or just under where the 3 tubes of the upper frame converge. Currently on order from ebay are: (all parts are off a yz125 1998) swingarm, linkage, monoshock, and bearing kit. Im going to go to the yamaha store today and get the pivot arm bolts ordered.
As far as numbers go I know what I have read about other peoples attempts on the xs650 site and a few others, but until my parts get here I cant get any hard data (giggity). I do know an xs400 swingarm fits into an xs650 frame and vice versa. A 1998 YZ125 swingarm fits into a xs650 frame as well, might need a small amount removed off either side of the swingarm. Biggest problem will be that the yz125 pivot bolt is shorter (get two, weld into one) than the xs400's and that the pivot bolt mount on the xs400 has a bigger ID so the pivot bolt from the YZ125 has play in it. Im thinking that a machined sleeve with the ID of the YZ125 pivot bolt/bearings and the OD to fit in the XS400 frame will do the trick but again, cant do anything till the parts arrive.
I think the stock exhaust looks horrible and I really hate the fact that it has a joint in it. Seeing as its going to interfere with riding anyway im going to just build some custom one off headers and pipes. In my head its a two into one on the right side that sits high with a yoshimura can.
In short the end product will be an '81 xs400 with a dirtbike rear and monoshock.
Im from the good old PNW, just north of vancouver WA. Ive got two bikes currently, a cb360 thats torn down into boxes and the motors getting a good going through on the bench right now and then an 81 xs400 which is the subject of this experiment!
Ive lurked and lurked and lurked forever and done plenty to my bikes in that time but I never thought any of it was really worthy of its own thread on here! Conversions for the XS400 seem few and far between, or well any documenting for them at least.
So the general plan is to take a basically stock running xs400 and turn it into a dual sport dirt tracker! There have been minor aesthetic changes to the bike (dirt bars, mirrors, turn signals, seat) and ive only really delved into the engine to get her running (cleaned and rough synced carbs, shims on the needles, new air filters, valve adjustment).
SO a little background on this idea! I live pretty far out side the city where forest access roads are much closer (and really much more fun) than the highway. I dont have a dirtbike and didnt really feel like buying one right now. I figured I would just turn my xs400 thats just sitting around not running right into a nice little dirt-to-street bike. The plan is to remove the existing swingarm, rear wheel and battery box from the bike. Once the frames cleaned up I can start to mock up the YZ125 swingarm and figure out where the monoshock mount needs to be on the xs400's frame to give good travel and avoid binding. Probably going to end up having the mount just below the gas tanks mounting bolt, or just under where the 3 tubes of the upper frame converge. Currently on order from ebay are: (all parts are off a yz125 1998) swingarm, linkage, monoshock, and bearing kit. Im going to go to the yamaha store today and get the pivot arm bolts ordered.
As far as numbers go I know what I have read about other peoples attempts on the xs650 site and a few others, but until my parts get here I cant get any hard data (giggity). I do know an xs400 swingarm fits into an xs650 frame and vice versa. A 1998 YZ125 swingarm fits into a xs650 frame as well, might need a small amount removed off either side of the swingarm. Biggest problem will be that the yz125 pivot bolt is shorter (get two, weld into one) than the xs400's and that the pivot bolt mount on the xs400 has a bigger ID so the pivot bolt from the YZ125 has play in it. Im thinking that a machined sleeve with the ID of the YZ125 pivot bolt/bearings and the OD to fit in the XS400 frame will do the trick but again, cant do anything till the parts arrive.
I think the stock exhaust looks horrible and I really hate the fact that it has a joint in it. Seeing as its going to interfere with riding anyway im going to just build some custom one off headers and pipes. In my head its a two into one on the right side that sits high with a yoshimura can.
In short the end product will be an '81 xs400 with a dirtbike rear and monoshock.
