In what Decade was my HM100 built?

[miniminibike]

I am having a hard time determining what Decade my Hm100 was built.

Hm100
159182P
9186D
Was it built in 1969-1979-1989 or1999 How do you tell when you have just the engine and nothing else. I know it was built on the 186th day shift D but can't figure out the decade.

 

[markus]

The P in the specification numbers is revisions made of that model in alphabetical order. Since its pretty high I would say it maybe the 90's. Late model black shroud with bare cast block, big fan looking recoil :shrug: just guessing on that didnt go looking up any part or anything though.

 

[creia]

Post some good photos of the engine.
Michael