I think it's a 1985 Yamaha RD 350 F, without fairing. http://www.motorcyclespecs.co.za/Gallery%20%20A/Yamaha%20RD350F%2085%20%203.jpg
Un petit lien utile pour l'identification internationale des RDLC ici, vraisemblablement une 31K...: http://www.rd350lc.net/RD350TYPE.htm
Honda CL 175? The CL series Hondas are streetbike-based twins with high pipes. This bike is a single and is one of the XL series - maybe a 250 but could be something smaller.
The style of pipe tells us this is a 1974 Honda XL 350 - http://www.cyclechaos.com/wiki/Honda_XL350/brochures - the 250 version was different with the pipe going over the top of the crankcase - http://www.cyclechaos.com/wiki/Honda_XL250/brochures . I owned one of those early XL 350s myself for a short time in 1976 before I traded it on a new Yamaha XT 500.