ORIGINAL: dennis
...As has been said many times the OS40FP, the Thunder Tigre 40GP and the Tower 40 were all completely interchangable in parts. I have seen motors with parts from all 3 of the motors combined...
Not sure about the .40 but the TT .10, .15, and .25 all have sprinkler venturies with the needle valve to the rear instead of centered.
Here is a TT .10 venturi:
George