The motor has A52 stamped on the jug. Not actually sure what that means. I thought A3's were port and A35's had reed valve. My knowledge of tomos only extends to 2 bikes I bought...one with a seized A35/reed valve that I got running and sold and this bike with a A52(?) that is port. Both bikes had targa LX tanks, tho most of the plastic faring bits were missing. This bike came with a biturbo pipe welded on and once I got it running was a fair bit faster than the A35 (stock) that I had repaired before. So now I've dumped more money into it than I spent on the bike :) and it is fun to ride. Fun enough that I was considering registering it. I doubt I want to go through the effort of getting a new title...my understand is that here in NC that costs $ and is a hassle. Maybe it isnt so bad for a moped, but most guys selling motorcycles without a title can't get much for them because no one wants to mess with it.