Any Pee Wee RC expert around?

Hello everyone

I received my first NIB Pee Wee RC and I am eager to test it.

One thing caught my attention and got me quite surprised: the exhaust throttle sleeve has something like 1/16" play up and down along the cylinder. When the sleeve is down it totally shuts the exhaust ports even when rotated in the all open full throttle position. But gravity will tend to keep the sleeve down.. so the ports shut all the time? How can the throttle work if the ports are never open?



In the pic below you can see the throttle sleeve in the full open position. Only if I push the sleeve up I can see some light across the cylinder ports.
If I let the sleeve "fall" down it totally closes the exhaust ports.





I also uploaded a - quite boring - video on Youtube to show the play:


Is this normal? should I put some kind of shim under the throttle sleeve to keep it in the "up" position so to have it let the exhaust ports open when it should? or will it work anyway this way?

Thanks for your attention!

Andrea