Yearlier this year I was in Baja, A trip I've been wanting to do since I was was 10 yrs old after hearing and seeing pictures of the Baja 1000. I'm now 37 and was getting the chance to go. Long story short, The bike was running awsome, a little smoke on start up but goes away, typical of the old xr's (old valve guides). But really it ran awsome, usually 1 or 2 kicks to start in the mornings and even after crashing. Well 4 days in to the trip, That's the bearing for the counter balance shaft. Some extra carnage. I know this doesn't typicaly happen on xr's, but to it's defense, I've had her for about 8yrs now and numerous topends in various configerations from bone stock to 440 power, This thing would top out at 98mph (per my GPS). Luckily I got back, thanks to my girlfriend coming down to get me. And I wanted to do something differant with the bike than most ppl would do, make it electric start. I was already planning on this for awhile now. Found an ex400 bottem end on craigslist for $100 and a wiring harness for also $100 a few yrs back, so all is sitting in my little garage when I got back. Someone had said that the motor was not a direct fit. This would be a show stopper, so I cleaned up the engine cases and put it in. It's close, but the bottem front mount does appear to be off, but the counter sprocket shaft looks good to continue. Now I also wanted to do something else with this thing, because I can, Give it a kick start as well. Know I'll have 3 ways of starting this thing. 1 .electric, because I'm getting old and lazy, 2. kick if the battery dies and if that happens 3. push start. I ended up talking to another ADV inmate (forgot his name, sorry) one day, because he had done this and said he hard a hard time getting the E-start reliable, but once he did he said it was all worth the trouble. So I'm on a mission now, I have the whole bottem end of the ex motor and various parts to the xr. I found be using the counter sprocket shaft from the xr (replaced 3yrs ago, should be good) and putting all the ex transmission gears on that shaft would allow me to put the kick start gear on. This bushing will go on the xr shaft to allow the gear to go on, I suppose if you had the means you could have the ex shaft milled down, but I have the shaft, bushing, and gear. And it goes on like this. and will look like this once all is in place.