That's a great question Lorne because I have the exact same situation/question.
I picked the same snowblower up last week at Sears. I never even thought for a second there would be no throttle until
I started it up. I noticed however the upgraded SNOWMAXES with the Briggs and Stratt come with a throttle. On the 9.5hp there's a cover plate where the throttle should go.
I don't have the answers to your question. Hopefully someone answers the post.
james
November 2007