Numbers, Exhaust, Porting early CR250

I have a CR250. It has no numbers anywhere I can find. Looks like a 1978 to 82 maybe. I can't figure it out. I have check the bottom. No hole for id plate on top. I don't have a clue.

If it is a late 70's model, what is the best pipe for vintage racing. Vintage iron offers the retro rocket, butr they are for the MN frame I beleive.

Also, what about porting for vintage racing?

Thanks

timothy.g.lancaster@doc.mo.gov

(314) 412-4510

Pictures???????

l belive factory replacement cases had no #s stamped on them.

Here is a picture. Can anyone tell what year this might be.

77-79... no dog leg clutch lever, and a magnesium flywheel cover. in 81 the CR,s started to change those things.

Do you know where can I find an aftermarket pipe for this model, or a good stock pipe? I have the ML frame.

id have to check,i may have a stock pipe. for a 79

my 78 CR 250 HAS AN 8 SPLINE COUNTER SHAFT, WR 250/390 HAVE 12, (1980) IF IT TURNS OUT TO BE A WR, SAVE EVERYTHING AND BUILD A WR 390! PERFECT MOTOR FOR US OLD FARTS THAT REFUSE TO GROW OLD!

Thanks! This is fun. My first foray into vintage.

I checked, my engine has 12 spines on courntershaft. Does that make it a WR? Do 250 and 390 top ends interchange on this motor?