I bought this 250R from a guy that did not know much about the bike. He just knew it was a 265 motor. My question is, I know it has a 86 piston, which is .50 bore over It also has a spacer plate on the bottom of the jug.
How can someone tell what kind of jug they have or if they have a bigger crank. Or is the bottom a 88 89 or the jug an 88 or 89?? Is there ways to measure these kind of things.
It looks like it has an 86 swingarm also. SO I think the frame is an 86.

 

Check my post in the other thread.

 

If it has an 86 piston w/spacer plate it would have an 87-89 crank. If its .5mm over it would only be 250cc right now. You would have to remove the cylinder to know the year, 85-86 has no intake bridge, 87-89 cylinders have bridged intakes.

 

Would I be able to see this bridge by taking off the carb and reeds?

 

Yes, you will be able to tell that way.