what engine is this

[maxamillion]

My bud has an old bike engine that was given to him and he doesnt know what it came out of. The numbers are F7E3516.
Anyone have a clue? It is an air cooled 2-stroke and has 2 spark plugs but it doesnt look big enough to be a twin cylinder. :confused:

Thanks

[Mxjunkie]

Its probaly a old dt175 motor that yamaha had, the 2 plugs is so when one fouls you can put the cap on the other, me and a friend bought one for 100 bucks and beat the living piss out of it for 4 months before it died lol...

[maxamillion]

hah..I guess thats one way to make sure your bike starts. Thanks for the info.

[PolarisRider06]

my 1974 suzuki tm 400 has two spark plug holes in it, one just has a plug (to fill the hole not a sparkplug) and the other a sparkplug but i'm guessing its the same thing as mxjunkie said. probably for if you fowl a plug while racing you could quick switch the wire over.