if that dont work you will have to buy a front caliper from a 98-05 yz dirt bike. i put one on my 86 trx250r. the holes that are threaded that mount it to the caliper bracket are only a 3/16th of a inch off. just egg the one out a little and it fits rtie on.
they are way cheaper + you dont have a 20 year old half shot caliper anymore.
the yz ones go for $10 to $20 dollars on ebay compred to aruond $75 fior a 250r one. i just won one from a 2002 yz250f for only $10.
JASON LISKEY
1985 atc 250r ---- finsh line axle,.fmf exhaust and rictor privateer silencer, prm grab bar.
2008 KTM 525xc quad ----- HMF exhaust, HRE chromoly stem,
86 trx 250r --- with after market chromoly frame and everything else done to it
01 400ex --- with 86 trx 250r motor
87 250x + 93 300ex both 350x powered
2 = 86 atc 350x's
86 atc 250r
83 atc 185s --- from retired guy not ridden since 87
Bandito framed 110 with 85 motor and yellow us90 fenders + tank