Proper prop help.

[LRCXed]

I have a 1970 Glasspar 16' Citation with a 120. The Mercruiser IO is vin # 2550333. Engine ID is 3937746

I bought a new style Quicksilver prop with the replaceable center hub. When I install it the way the directions say to, the prop is held out to far and there is a gap between the housing and the back of the prop. The nut doesn't go on all the way either. Without the brass collar/spacer from the kit it sits properly where it should. The back of the prop fits on the OEM thrust spacers recessed groove this way. My question is weather or not this is the intended way the new style props are to be installed or did they sell me the wrong prop/kit?
The original prop is a 14X19. The one they sold me is a 14.5x19. And the box says it's for a MerCruiser Alpha one/Bravo one. Part # QA1916X. The hub kit is part # 835257Q 1.
Does anyone have information on weather this is correct for my out drive? And where can I go to confirm what I SHOULD have on this IO. The out drive serial # is 2650333 if that helps. And according to the info written in my book this is a 1970 boat.

I took the boat out a couple weeks ago but couldn't adjust the IO tilt so I could trim it out and see what the rpm was. I know that's important, but next time I take it out I can get that info now that I have the IO tilt system working again.

Thanks for the help in advance.

Larry

 

[jestor68]

Re: Proper prop help.

It sounds as if you may be using both thrust washers when trying to install the prop. Use only one thrust washer behind the prop. The one supplied with the prop is intended to REPLACE the OEM washer.

For reference, your 1970 MC-1 drive uses the same props as a brand new Alpha drive.

Are you tightening the prop nut properly; at least 55 lb ft. 65 lb ft is better. It takes proper tightening torque to compress the rubber hub and get it to fit tightly on the prop shaft .

 

[LRCXed]

Re: Proper prop help.

The thrust washer that came with the new prop is way to thin to use by itself. With the OEM spacer it seems to fit fine. But with the added brass spacer it's held out to far.
I have tightened down the nut and it didn't make any difference. I THINK it would be fine with only the OEM spacer, I'm just trying to get confirmation one way or another if it would be safe that way or if it's the wrong prop and hub kit. BTW, the new center hub for this is hard plastic that allows replacement without having to have it pressed in.

Here's a few pics of what I'm dealing with. This is the OEM hub with the prop sitting in the correct position the way it's supposed to be.


This is with the added spacer that came with the hub kit. You can see how much it sits out.

 

[LRCXed]

Re: Proper prop help.

As you can see the OEM hub fits fine in the back of the new prop. Will this be ok to run this way?

 

[jestor68]

Re: Proper prop help.

If the prop fits properly on the old style thrust hub, that's what you have to do. I assume that everything fits with the rubber hub system in place.

Torque the prop nut to 60-65 lb ft. Recheck the torque after the first use and every 20 hours of operation.

Grease the prop shaft splines before mounting the prop.

Enjoy your classic Glasspar.