Engine ID number??

[Vonturd]

I need help finding out what year my engine is. The man I bought it from said the frame is a 79 but said he wasn't sure about the engine. Where can I find a number on the engine and where online can I find something to find out the year?
I've seen the posts about ID'ing the bike frame but not the engine. If anyone knows please let me know.

 

[gggGary]

Behind the Right front engine mount and tach cable stamped vertically, the engine number matched the frame number when they left the factory.

 

[Vonturd]

Thanks gggGarry. I'm on my way to check that out now