RE: GMS Engine Tuning Problem
You may want to contact this Australian company who has GMS engines in stock [link=http://www.modelaeroproducts.com.au/shop/index.jsp]Model Aero Products[/link]
I've not had much contact with them but believe they can source parts for most GMS engines. The exchange rate is 1USD=0.93AUD so those in North America should be able to offset the postage costs with savings on the exchange rate.