My advice... Win lotto, build three. One for yerself, I'll buy one, send the other to suzuki so they can see how a real bike is made. Seriously now, I've been thinking of this myself. Would like to see pics of the madness as you go.
will do! where the project stands now: 1. bought running '93 tz250. frame, forks, s.a., shock all good. 2. removed bodywork, weighed the bike f=108# r=95# 3. dropped motor. weighed 60# 4. sold the tz motor, carbs, pipes etc. http://www.tz250racing.com/cgi-bin/forums/ikonboard.cgi?;act=ST;f=6;t=3172 5. bought running '02 xr650r, all stock, low milage. ( decided on the honda motor as opposed to yam. 660 on advice from a local engine builder phil wyatt) 6. dropped 650r motor weighed 86# 7. hung motor in chassis, looking for mounting method and weighed the bike. front was appproximately 20# heavier than rear. i think this can be overcome by mounting all black boxes in rear. plus pipes will add more weight to rear, etc. goal is to have the weight distributed around 51% f, 49% r. should keep the front a little heavier since the tz's have such short wheel base and not much trail. 8. hung the 650r motor along w/ carb and chain to find center of mass. will mount motor in chassis balanced. then will need to mount everything else balanced as well. pipes, boxes. rad. etc. 9. i will be paying a bike builder to mount the motor in the chassis. he has good experience with these one-off projects although he has never done this particular combination. he has done cr80s in rs250 frames for cmrra (mini road racing) and he has just finished a tz w/ a yam 426. will be dropping the bike off w/ him around 2-7-06. will post pics when i get the bike back. 10. after getting the motor fitted i will be sending it off to get built. **goal is to finish at less than 250# w/ at least 70rwhp
COOL!!! did you cut the rear swig arm and use the rear motor mount? btw my builder will be fabbing a cradle, he said that if you do not use a cradle the motor will move around too much. will you be racing it? if so, where/what class? i plan on doing formula singles at wsmc and clubman/dss/dsb wera.
Here are a few more shots: http://www.12pointracing.com/gallery/view_album.php?set_albumName=thumper The swingarm didn't need to be cut at all. I had to for a KX500 motor, but for at least the old XL motors it clears just fine. Mine was not hung by a cradle - just on the head and on the rear lower motor mount. It has yet to be run or even completed, but I at least trust it will hold up since it was done by: http://www.barebones.net/ Jay Wright is the mastermind behind Barbones Machine, and he happens to live a few hours from me...He is a really nice guy and really knows his stuff when it comes to these little bikes. I will finish mine someday. I keep promising myself it is my "retirement bike" when I need to get back to my love affiar with TZ250s.
I started getting the required things together to run the megasquirt EFI as well on mine (just as was done in that thread). EFI is much easier, but I need a lighing coil for my XL motor to generate some juice and keep the thing going for more than a handful of laps. I was thinking of a TLR or Ducati throttle body too fwiw...
Is the Xr650R the water cooled version? I have a TZ250 with a RS/XL/XR600 that now displaces 700cc it is one heck of a torque monster 50 ft/lbs but only 63 hp and it does not like the revs worth a darn if it is the same radial valve head you need to look into getting all the rocker arms hard plated by Mega-Cycle to survive even mid sustained 5000rpm.
as i said, i dropped off the chassis and motor with tommy crawford on 2-7-06. picked it up on 5-24-06. still need to mount oil pump, build an oil tank and figure out where to put the radiator(s). i can't use the tz radiator any more since the motor is too far forward and the radiator would make contact with the front wheel. i will prob need to mount the original xr650r radiators outside the engine and frame spars on each side. with a little tweaking of the bodywork there seems to be enough room but they will be goners in a crash. i still need to get the engine built too. i'm still a couple of months (best case) from getting it on the track. btw, i think tommy did great work mounting the motor, building pipe, reforming the tank. (he got his start working at harris in england)
My advise.................don't continue building it as I wouldn't want you to make me look very slow................ :tut: Honestly though, this is one of the coolest project bike, and you'll be kicking asses with it! It surely looks great. You just got to make sure you can work out other stuff, especially the radiator part of it. Now I am going to see if I can find enough parts to build a special project bike as well. :up:
i have a completed tz650r. 94 tz chassis, 2000 xr650r thumper with hrc piston/cam power-up kit. i came out about 260lb. it is fun for sure. i've done a few track days and it's the accordion action, silly corner speed but eyeballs get sucked out by big bikes in a straightaway. still doing better lap times than on my 600.
poorwrench, where did you mount the oil tank and what is the capacity? what kind of radiator / oil cooler setup did you use? what is your weight distribution front wheel and rear wheel? thanks!!
i'm racing a XRR supermoto and just love the bike the 450 motocross engines just don't last is the problem the 650R is just awesome I got the stage 2 hotcam- edlebrock carb/full FMF tit. exhaust/weisco high comp. piston ect...tops out at around 124-i can keep up with duc750SS no problem can't imagine the TZ650R bikes-that would be sick
Yeah I can't wait for my YZ450 to go pop. Any preventitive measures to avoid the piston coming out of the case?
Yeah, take it apart and check it a lot. There will be play in the rod bearing before it goes. The mains are also prone to wear. Don't run a really thin oil ie:0-30, 5-30, the thicker stuff seems to make them live longer 10-40 +.
singles Very cool! Hey wsmcrobert could you post a tight shot of the countershaft to swing arm bolt area, and tell me also what the center to center measurment is, thanks
