Rotor position vs Piston position

[Jim Recker Jr.]

With the carb removed and looking in the rear port, you can see the rotor in a position that reveals the rod. So I get the crank pin in the proper rotor slot, what position should the piston in? All the way top or absolute bottom?

 

[Tim_Duggan]

Inlet port will be open at TDC.

 

[Jim Recker Jr.]

Perfect thank you sir. The reason I asked was over the weekend the carb wouldn't draw fuel. Thought maybe I had the crank in the wrong rotor hole

 

[Joe Warren]

Jim you did not say what motor this is??? the crank pin should go in the hole closest to the intake opening in the rotor...... as someone stated above... Installed correctly... The intake rotor will Still be Open at Piston TDC & teh rotor will close the intake opening about 58- 60 crank degrees after TDC. Make sure you are turning the engine in Correct Rotation while you are looking into the front of it. also make sure your starter is rotating the correct direction for the engine to run?? P.S. IF YOUR DRUM ROTOR HAS 2 DIFFERENT PIN HOLE LOCATIONS?? THE HOLE CLOSEST TO THE OPENING IN THE ROTOR IS THE CORRECT ONE. jw

 

[Jim Recker Jr.]

Cheers Joe, this is for my OS Max 46. We checked the rotation of the starter and also made sure the pipe pressure line did not have a leak in it.

 

[Jim Allen]

Jim you did not say what motor this is??? the crank pin should go in the hole closest to... the intake opening in the rotor. as someone stated above... The intake rotor will be open at ATDC & will close the opening about 60 crank degrees after TDC. Make sure you are turning the engine in Correct Rotation while you are looking into the front of it. also make sure your starter is rotating the correct direction for the engine to run?? jw

The rotor will open some degree amount ABDC. It could be from BDC to 44 deg ABDC in a nitro motor.