anyone know what motor i have?

[cabbage]

bought the bike off craigslist, never asked as to "brand" of motor. the little focker sure hauls *** though!

 

[Al.Fisherman]

Brand??? Very hard to tell. There are a few Chinese companies that make engines that look just like that. I've bought 4 and they came from two different companies, and all look close. My first had a clutch arm (straight) like yours, the other 3 had bent arms. All 4 engines I bought with slant heads, and all were 66cc which you can't tell (as far as I know) them apart until head is removed.

Although I wouldn't buy from them again, that looks like it came from "Luckyearlybird" (read my signature) they sell on e-Bay.
http://cgi.ebay.com/80cc-bicycle-mo...Cycling_Parts_Accessories&hash=item3a5b425a91

http://cgi.ebay.com/Motorized-bicyc...tem&pt=LH_DefaultDomain_0&hash=item23076ce3b9

http://cgi.ebay.com/80CC-BICYCLE-MO...tem&pt=LH_DefaultDomain_0&hash=item2c504c50c8

We have a number of vendors here that sell parts. Most parts are the same between brand to brand. In fact (and I can stand to be corrected) you can make a 66cc out of a 49cc, by changing the piston. rings and the cylinder...not sure about the head.