New prop doesnt fit. Store I bought it from seems giving shady advice.

[LAC_STS]

Well, per my earlier thread about my prop slipping I went out today and bought a new prop.

I bought it from Marine Surplus. They are a store that is exactly what theyre name says. They stock a BUNCH of surplus marine parts they get from wherever. They have TONS of props, and they told me I could try them out as long as I returned each one within 48 hrs and in the same condition as it left.


I have a 5.7 OMC / Cobra on a 25 ft Donzi. The prop I have been using is the one that came with the boat that the PO put on there. Its an aluminum 15.5 x 15P. It is beat to h***. The blades are nicked bad and now the hub is spun.

WOT RPM is 4800

I was hoping that if I got a 14.5ish x 17P SS that it would keep the WOT RPMs about the same because of the added efficiency of SS and that my current prop is in such poor shape.

So today I bought a Ballistic 14/75 x 17 SS. I tried putting it on but it wouldnt slide on enough to get the rubber washer (with the teeth for the splines in it) to go on. Talking about the one that goes before the nut. You put the prop on then the washer then the nut then the cotter pin.

There is almost none of the splines from the shaft sticking out and I can feel where the prop meets the lower unit that the part that should slide into the lower unit is not sliding in there enough.

I took it back to where I got it and at first they told me that I don't need to use the washer just to put the nut on. I told them that cant be right because then the nut would be sitting on the little bit of spline that is showing. Then they said I need a new thrust washer.

I took the thrust washer off and flipped the prop over and set it in there and it does NOT sit flush.


So whats up with this? Do I need another thrust washer? Do they make thrust washers that are thinner or that will sit in the new prop right? What should I do?

I want to try this prop out and see how it is.

 

[riptide09]

Re: New prop doesnt fit. Store I bought it from seems giving shady advice.

I have 2 OEM Johnson/Evinrude props. One got mangled enough where they were not sure it could be fixed. I was going away and wanted to take a spare so I bought a new Johnson/Evinrude prop.

I went to put it on and see if it fit before leaving and I had the same problem you are describing. The prop would not slide on the shaft far enough. The new prop came with a thrust washer but I left the old one on. I compared the thrust washers and sure enough they were different.

The original washer was flat. The new washer was not.

Original washer style:

New washer style:

The new washer had to be placed with the smaller diameter side facing the prop. The hub of the prop fit over the smaller diameter allowing the prop to slide on enough for the prop washer and bolt to fit.

Look over the hub for differences. You very well may need a different style/size thrust washer.

 

[LAC_STS]

Re: New prop doesnt fit. Store I bought it from seems giving shady advice.

Thanks riptide09


UPDATE:

I took the prop to a local prop shop called General Propeller. I brought them all the pieces, including the thrust washer, prop, nut, washer that goes before the nut, and the old prop.

They looked at it and said that the hub on the new prop wasn't pushed in all the way and that if they push it in the thrust washer will fit correctly and the prop will fit right.

It was getting late so they said they couldn't do it till tom. I just brought the prop back to where I bought it and they said they would exchange it, give me a refund, or give me $100 back if I wanted to keep it.

I only paid $275 for it so I took the $100 and kept the prop. I went back and dropped it off at the prop shop and will pick it back up tom and post the results.

The prop is brand new so I dunno how the hub could not be all the way in. The hub looked fine to me so I dunno.