Installing propellor on Force 150

[HotTommy]

I removed the propellor from my 1993 Force 150 to record the prop specs before I test it. I removed the nylock nut from the shaft, the tabbed washer, the large brass washer with notches for the tabbed washer, and the propellor. I was surprised to find that the two washers moved very freely even before I loosened the nut. I'm sure they did not engage the nut well enough to secure it.

I've searched without success for instructions on how tight to reinstall everything. So what are the steps / specs for installing the propellor?

 

[Jiggz]

I'm not sure if there is a required torque for tightening the locking nut but for sure there should be no play on the propeller once it is tightened. There should be three components as you mentioned on top of the propeller and one spacer behind it. The orientation of all the components starting from an empty prop shaft is the spacer, prop, splined washer, tabbed washer and then the locking nut.

 

[pnwboat]

Not unusual for there to be some slop in the propeller even though the nut is tightened down. I think it has to do with the after market propellers for the older 3, 4, and 5 cylinder 4 inch diameter gear cases. This gear case is not as common anymore and propellers specifically for this gear case are getting more scarce. Fortunately, the differences with the after market propellers are minor and easily overcome. I just add a washer to take up the play.

 

[Frank Acampora]

There is usually about 1/8 to 3/16 inch of the splines showing past the propeller hub. The large bronze washer with notches is splined internally to match these splines. This is how it locks the tabbed washer and prop nut. VERY often, the splines strip out of the large bronze washer and if the nut is not fully tightened, then the whole assembly of washers and nut can move.

IF the bronze washer has stripped its internal splines either buy a new one OR be certain that the prop nut has a good nylock insert. Be certain to tighten it "grunt" tight-- I would say 30 Foot pounds or so. If the washers are still in good condition, then tightening the nut snug and bending one tab is sufficient to retain it.

 

[HotTommy]

The large notched washer looked like it is time for a new one. I plan to run this propeller (13.5 x 17) just long enough to decide what size new propeller to get. I'll replace the washers when I replace the propeller.