Raptor 30/50 v1 assembly manual
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Note about balance: If you have high frequency (above 10,000 hertz) vibration problems that you are trying to locate, then often times it is from the fan. If you have a high point balancer then check the fan before installing. I suggest checking it with the clutch installed, otherwise the cone of the balancer does not center correctly due to the threads in the top of the fan hub.
*Tip: With the fan installed there should be no in/out play in the engine crankshaft. When you pull on the fan there should be no movement. If you develop any play in this later on, for instance when you try to crank a fuel-locked engine, then this can cause engine tuning problems. Refer <here> for more info.

First remove any washers from the crankshaft of the engine. Next put a little blue loctite on the threads of the crankshaft and screw the fan (3) all the way down. The bottom of the fan hub should be against the front bearing of the engine. There should be no in/out play in the crankshaft*(see tip at top). Put a drop of loctite on the threads of the crankshaft nut and tighten the nut as hard as you can. If you don't get it tight then it might unscrew when you go to start the engine. If this happens you will notice the start system locks up, this is because when the fan unscrews it is shoved up against the top of the clutch bell. The original manual says to use a towel to hold the fan while you tighten the nut. The best method is to make a <fan hub tool> like I did. Basically you just drill one big hole and two bolt holes in a plate of metal. Click on the link for the details. Two other methods of getting the prop nut tight are: use a crankshaft lock (delrin block that goes where the backplate is) or you can also use the technique of using a plastic toothbrush handle to do the same. Some people have had sucess using the piston lock tool (screws in place of the glow plug), but beware that this can dent the piston.
Next place the clutch shim* on the bottom side of the clutch (2) and attach it to the fan hub using two M3x10 bolts (1), use blue loctite on these two bolts. The bottom of the clutch is the side that will fit into the center of the fan hub.
*Note that if you install the shim upside down the straight edges of the shim and the clutch shoes will not be parallel.
Note 2: Do not overtighten the bolts, this could lead to failure and confirm the head of the bolts are against the clutch. In some cases the threads in the hub may not be drilled all the way and this will leave some up/down play in the clutch. This will cause the bolts to break as well as possible clutch failure.

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