Can you I.D. this crank ?

[84scrambler]

Found this in my parts box , I think it may be a early to mid 70's 250 not sure tho. I'm thinking of selling off some parts that I will never use and some one may need this.

I.D. of top of rod is .850th = 21mm
eye to eye 4"and 15/16 =125mm
Ign. side .984 =25mm
clutch side on raised lip 1.102 =28mm

I hope I got the cross reference right to mm .

 

[jimspac]

By the size of the flywheel I would guess at 72-74 big case 250 seeing the big end is not close enough to the OD of the crank cheek to be for a 400 or 450

 

[84scrambler]

Any other info needed for I.D. ing this thing ?

 

[jimspac]

Maybe a shop manual for verification purposes. The crank bearing journal measurements you gave are very common with engines going into the 80's

 

[GaryM]

The pin location in the flywheels doe not look like 80s cranks to me in pics

 

[84scrambler]

It was in my 79 wr 250 and the piston was about 3/8ths from the top of the cyl. so the rod is shorter than a 79 250.

 

[justintendo]

It was in my 79 wr 250 and the piston was about 3/8ths from the top of the cyl. so the rod is shorter than a 79 250.

that or the rod is the same and the cheeks are different?

 

[jimspac]

So definitely an earlier crank than 1979 with a 125mm center to center on the rod. Rod length does not affect stroke but does affect stack height

 

[jimspac]

The pin location in the flywheels doe not look like 80s cranks to me in pics

I did not say it was an 80's crank but noted the crank journal diameters were common with later cranks

 

[84scrambler]

I found a pic of the two side by side the 79 wr 250 is on the right and the mystery is on the left.