Hey, I'm a stroker too! I'm a Honda SS50 owner from Holland. In Holland the 4-stroke moped was very popular in it's day and so there still are quite a lot of them around. I''ll give you the URL of the website of 4-stroke bike centre, they've got an international postorderservice http://www.4-strokebikecentre.com. There also great for advice: firstname.lastname@example.org
I'm afraid the site is in Dutch, but you can adress any questions to his email.
The Honda fourstroke mopeds are considered to be the best mopeds of the world. They use half the feul a 2-stroke uses, the engine lasts 5 to 10 times longer than most 2-stroke engines and the driving comfort is out of this world.