How can I obtain a spare part?

I am fairly sure it uses a zama C1U CARB.
You should remove it and look for the model number and brand.
If you take it apart you can see all the parts gaskets diaphram etc. I go to ebay to look at the kit parts and see if they match with mine to get the right kit #.
Then you can shop for price online if you want.
Lowest prices HERE
http://www.mowpart.com/carburetor-zama-p-2718.html
Be sure of your carb make and model numbers

Bob
March 2008