TOPIC: Mercury Quicksilver prop

Hey All,

Need original Merc 2-blade bronze 48-30390-17
Anyone have a NOS sitting on the shelf?


Or ideas to repair spun hub?

Thanks,
Terry

If you have a propeller repair shop in your area, they can re-hub your prop for a nominal fee. It'll be as good (or better) than new.

You can also adapt a "modern" prop to your classic Merc. I'm assuming your propshaft has a square shoulder where the bell-shaped propeller thrust hub rides against.

Well, if you pick up the correct spacer (P/N 23-86918), you can use the commonly-available flat thrust hub and a new-style prop. You may find that a 15"-pitch, cupped 3-blade aluminum prop gives you better acceleration than your Stone-Age 2-bladed bronze prop, while giving you a top end that's at least as good as what ya got.

There's a spacer on eBay right now for $5.99 shipped. You ain't gonna find one cheaper than that unless someone gives it to ya!

The P/N for the flat thrust hub is 75282 and you'll probably find lots of old stock for that superseded number. The current P/N is 13191K01, and IDK what's different about it from the old washer, definitely more expensive! Marineengine.com still stocks the old part as well as new. Cheap as $10.05 shipped on eBay.

One caveat, with your special water-intake trim tab, you won't be able to use a prop with a ton of rake. The swept-back prop blades could hit the trim tab/water pickup. On a later-model engine with removable trim tab, you can merely replace that with a trim tab with more set-back. There ain't any of those for your old Merc! BTW most props in the pitch range that your engine will handle, won't have a ton of rake and should fit OK.

HTH.............ed

Good information, so I will steal some knowledge here. Also Terry, I am lucky that I have a prop shop 2 miles from me that most boat repair shops send off their props to for re-hub or almost any repair. I have one of my old 2 blades re-hubbed a couple years back and not too expensive. I can check my prop collection and let you know what I have.though the 2 blades look cool, I know Ed knows his stuff and agree a 3 blade is bran probably best. For fun, you can try my 3 blade 17 next summer just to see where it tachs out so you know what pitch suits your cruiser best.

Thanks for the recommendations Ed.

Talked to couple local shops and they never worked on bronze props.
Old timers Dick’s Marine in Fox Lake referred me to AirMarine in Chicago.
www.airmarineinc.com/



Took it down there and they will re-hub and repair and balance the prop.

They recommended an upgrade to a modern 3 blade too and also said the thrust hub needs to be replaced.

Would you believe I actually have a Michigan 3-blade bronze SMC-893.


It crosses to the Merc 48-3146A3 and is 15 pitch. The AirMarine folks said it would be a good selection.

The original owner of Mama Mia! gave it to me and said it was the ski prop. I just never swapped them out.

Hey Dr Go,

Thanks for the offer and I'm gonna try the 15 and figure where to go from there.
The 61 Merc owners manual warns against WOT using ski props with no load.


If your travels bring you near Chicago next Sunday come and see us on the Riverwalk Downtown Docks at the City Winery.

Terry

Terry, surprising those shops don't know how to work on bronze props, just think of all the inboard prop repair business they've lost! And the hub replacement on your prop is no different than the process for a newer Merc aluminum prop.

Based on your video where you got 35mph at 5000 rpm (and that was with the 17 pitch, right?), the 15" pitch should give you 5200-5300 more-or-less, and you should have an improved hole shot and perhaps better top speed. The old Glasspar hull is a lot for an 80hp to push so that's a pretty good turn of speed for a boat that size.

Once you get a new baseline with the lower-pitched prop, we'll be able to make better recommendations if you want to upgrade to a more modern design. Maybe even a stainless prop, which would give you even better performance than a modern aluminum prop.

FYI, the old Mercury prop charts show a recommended full throttle rpm range of 4800-5200 for a FGS 800-Six so you should be right in the ballpark with that 15". BTW you're not gonna hurt that engine with a slight overrev, all the old Inlines like to spin up to make their power.

Have fun on the water...........ed

Thanks much! All good information and the folks at the prop shop say the same about using the 3 blade 15 pitch.

I was half joking and wishfully thinking about a NOS prop but that is just what I got.

It’s a 48-29658-17 although Michigan Wheel shows it as a replacement for the 48-30390-17.

AirMarine had it on the shelf and they been down there since 1940 so who knows what they have.

Gonna rehub the original and keep as a spare as the Merc owners manual suggests.

And still gonna play with that 15 pitch too next week.

Terry

Did you buff your own prop? If so, who has the best procedures and compounds? Seems like somewhere I saw a big wheel on a bench grinder that looked originally white and a bit soft, but very gray looking like some sort of polishing compound. I have one shiny prop and my other 4 bronze need buffing and I would like the methods (secrets) to making mine shine like the ones in your pictures! Great thread of information. I need to connect my Airguide tach before next summer so I can play the prop swap game and dial it in. Props truly can make or break how any boat performs.