newbie prop question.

Hi all, I am doing winterizing for the fast time on my boat 1989 force 85hp. I have a few questions about the prop.

1) My prop is kind of loose when it is on the lower unit, I double check the nuts and it is all tide. by can prop can be slice up and down about 1/2". When I am driving it feel ok though. since this is my first boat, I have no idea if this is normal or not.

2) I remove the prop and it look like there is some wroning to the prop and the lower unit. please look at the pics below and let me ok if this type of worn is ok






This is the worn parts "cycle in yellow"




These are the only things that goes in after the prop. am i missing some parts?

Re: newbie prop question.

Ayuh,..... There's Supposed to be a Thrush Hub ahead of the prop....
You don't have 1....






edit; Benchmark, Posts: 24,000

Re: newbie prop question.

I was thinking I am missing something...... do you know where can i get one?
I got this used boat and it does come with one. I need to replace it befor it eat up the prop and the lower unit housing.

Re: newbie prop question.

Pop into your local marine dealer... I'm gonna say your I/O drive is a Mercruiser and pick up a thrust washer for your prop which is definitely missing and why you're seeing the grooves on your prop. Depending on what drive unit ya got, you'll need to pick up one of these. IBoats should be able to hook you up with one for next weekend's outing.

http://www.mercstuff.com/thrustwashers.htm

Re: newbie prop question.

You need a thrust washer. Any local Mercury dealer will have one. Those lower units were the same from 1979 to 1994 so any year thrust washer for any 85-125 engine will fit. The thrust washer is a large thick washer with a tapered hole to fit the prop shaft and a land so that it plugs into the back of the prop. OFTEN The thrust washer will corrode into the prop, stick, and come off with the old one. Those who don't know will simply replace a new prop without one.

NOW, Just so you know: The previous owner installed the prop without the thrust washer. The prop bore against the lower unit case while the engine was running and wore it until the hub moved down far enough to jam on the prop shaft splines. I am surprised you did not have difficulty pulling the prop. The anode wore the grooves in the prop webs. (last photo circled in yellow) The damage is not terminal and the lower unit and prop will still function properly. You need not do any repairs except install a new thrust washer.

However: when you do install the thrust washer on the shaft behind the prop, your gearcase will have worn about 1/2 inch. So the part of the prop hub (relieved flange) that normally would sit inside the gearcase will be mostly exposed. This is only an aesthetic problem because your engine does not have thru- hub exhaust. Thus: you do not need to worry about exhaust leahing around the flange and fouling the prop blades.

If you are interested: You can gauge how much was worn off the gearcase because there should be about 1/2 inch past the small radius at the end of the leg. (Just above the top screw holding the anode in place) Alternativly, the prop flange should only have about 1/32 to 1/16 inch gap between the prop hub and the gearcase.

Re: newbie prop question.

Thanks for the info but the motor I have is a 1989 Force 85hp. Will the Mercury thrust washer fit? the place I live I have no marine dealer near by. Can you tell me is there any web site and the item # for the thrust washer?

will this work? http://www.iboats.com/mall/partfinder/?*******=578137082&gd_grid_id=223&gd_partfinder=1&gd_poid=111393&gd_row=3&**********=575582724
Thank alot.

Re: newbie prop question.

No, that is not the correct thrust washer but it would probably fit. However, you might have problems with the prop washer and nut.

Yes, the mercury will most likely fit but the most probably number would be the Sierra 18-4220. That is the stepped washer. Expensive, aren't they?

Strange--I looked all over iboats and could not find one listed for Force engines, so unfortunately, you will need to take a chance.

If you call the 800 number before ordering and ask if it will fit a 7/8 inch shaft, hopefully they will be able to tell you.

Re: newbie prop question.

thank you very much, will give it a try.