The 1974 & 75 cyl have the same external casting. The 1974 cyl has only four transfer ports plus the exhaust and intake. The 1975 cyl has a boost port in the rear transfer port that dumps fuel out of a small port that exits right above the intake port. The 1974 CR125's had very fine threads on the cyl studs to mount the head and on the case,s to mount the jug (these fine thread nuts are no longer availible from Honda!), the 1975 & 76 cyl had the standard 8mm x 1.25 threads on the studs. The 1976 cylinder has a noticibly larger outer casting and fin area at the top but the same mounting area at the base, the 1976 cylinder also has a MUCH thicker liner that will not fit in the 74/75 case's, this was due to the fact that Honda used the same outer casting for the new MR175 and needed the sleeve area big enough to accept the 125 or 175cc liner for either bike it was being used for in production. With that being said you must also know that the same base gasket will fit on all years without the jug mounted but that the 76/77/78 cases have a much wider opening front to back to accept the bigger cylinder.
Monday July 11, 2016 @12:00 am
The Best Looking Bike of all time
and the 1987 CR125 too
Tuesday June 28, 2016 @12:00 am
A Beautiful Never Raced 1983 YZ125K I restored this unraced bike over 12 years ago 95% OEM Parts $3500.00 Call Text or email us