id think about £1000 for one in good condition but if its got engine problems then i wouldnt risk it for any amount of money.

you have to rev them to 18'000 rpm (they rev to 20'000) to get any power from them and at that engine speed problems arnt good.
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Honda nc23 CBR400 AERO 1986, 1990 honda NC23 Tri-Arm, 1987VFR400 NC24 Rothmans Rep, NSR250 MC16 1987, CL250s 1983. Moto guzzi zigolo 110cc 1958. Fantic 50cc 1972. Suzuki Cobra Race bike 500cc 2t 1975 , GP125 1975. Triumph T110 1954. BSA Thunderbird 1955. Ariel VB 600 1952, 1990 MuZ 125 etz.