Vintage Dirt Bike Q & A

Has anyone used a 1980 CR250 Bottom End in their 78-79 CR250? Is it possible?


J

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#829 The "Factory Novice"

1988 Honda CR250RJ
1983 Honda CR480
1981 Can-Am 250 MX6-B
1979 Honda CR250RZ
1979 Kawasaki KX250 A5
1978 Husky 250CR
1978 Honda CR250R
1977 Yamaha YZ400D
1977 Suzuki RM125B

The complete crank assembly, bearing and oil seals are common between the 1978, 1979 and 1980 models. The crankcases have different part # but I remember someone saying that the complete motor (without top-end) will drop right into any one of these frames. The crankcase differences are minor - like additional strenghtening webs in the casting.

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Michael Stiles
1979 Honda CR250R Elsinore | 2006 Husqvarna SM510R | 2007 Service Honda CR500R-AF

Thanks Michael!

J

_________________
#829 The "Factory Novice"

1988 Honda CR250RJ
1983 Honda CR480
1981 Can-Am 250 MX6-B
1979 Honda CR250RZ
1979 Kawasaki KX250 A5
1978 Husky 250CR
1978 Honda CR250R
1977 Yamaha YZ400D
1977 Suzuki RM125B

J

Check out the previous posting on this forum (currently about 5 pages back) titled "78-80 CR250 Interchangeablility".

Robert

Robert,

How the heck are ya? I should have searched before posting.

"All parts for the '78 to '80 CR250 bottom ends are pretty much interchangeable; however, there are several parts that were upgraded from year to year; the most noticeable would be the cases. The '78 cases lacked a shield behind the clutch lifter area (in front of the counter shaft) to protect the lifter recess when the chain gets tossed. Both the '78 and '79 left case halves lacked the three vertical support webbings at the area of the left transfers; which provide support to the base gasket area. And of course, everyone knows about the kick start pinion, clutch basket and ignition."

I guess I still want to clarify. The 1980 CR250 lower-end will work and has improvements to the areas you mentioned (webbing, pinion and basket). I have a chance to pick up an 80 lower-end, but I don't want to waste my money if it wont fit my 78. Thanks!

J

_________________
#829 The "Factory Novice"

1988 Honda CR250RJ
1983 Honda CR480
1981 Can-Am 250 MX6-B
1979 Honda CR250RZ
1979 Kawasaki KX250 A5
1978 Husky 250CR
1978 Honda CR250R
1977 Yamaha YZ400D
1977 Suzuki RM125B