Tired of Jury-Rigging! / Bad New Prop?

[davemoore]

We've had our used boat for a little over a year now, and are still finding jury-rigged garbage on it every time we touch it... but I think today's find tops the charts.

I recently bought a new prop right here on iBoats - a 14.5 x 17 Solas 4 Blade Alum with Rubex hub. When i went to put it on my Mercruiser today (replacing a 14.5 x 19 - 3 blade), I made a very disturbing discovery - the old prop (which is trashed) has been running without a hub! The only thing holding the back end of it (nearest the drive) was the thrust washer, which I couldn't get off no matter how hard I tried. The front (nut side) had a thing that was keyed in 4 places and mated to the shaft spline. It appears as though the new prop works fine though with the existing thrust washer - I checked the one that came with the prop compared to the stuck existing one using calipers and they're identical in size. But the nut that came with the new prop was the wrong thread for my shaft, so I had to reuse the old nut.

However, when I fired it up and ran it a bit just to see how it spins, I noticed a bit of a wobble... at first I thought I had a bent shaft, but upon closer observation I discovered that it's the prop itself that's wobbling - not the shaft.

Should I send it back? Is it a typical characteristic of the rubber hub? Not sure what to do. We're going out tomorrow, so I'll see how it runs...

Any thoughts?

 

[RicMic]

Re: Tired of Jury-Rigging! / Bad New Prop?

Personally if I bought a brand new prop and it was wobbleing right out of the box, I would send it back and buy a different brand.

 

[steelespike]

Re: Tired of Jury-Rigging! / Bad New Prop?

There have been some posts regarding the hub getting stuck in the prop
making quick change impossible without additional effort, wood blocks, standing on the prop to force the hub out.As far as the wobble you might check the shaft for run out. I would also run it to see if any vibration.

 

[Doernuth]

Re: Tired of Jury-Rigging! / Bad New Prop?

based on what you said I would have the shaft checked. The Mickey mouse job on the former prop is concerning.

Make sure that the new prop and hub are seated correctly and there is not some play or offset somewhere. Make sure that the old thrust washer isn't bent also.

Wobble will cause vibration and will tear up the lower unit if left unchecked.

 

[Wingedwheel]

Re: Tired of Jury-Rigging! / Bad New Prop?

I think the "jury rigged" thing you were seeing is a universal prop adapter. I've seen quite a few of those. They are generally made from aluminum so the will tear off just like an aluminum prop. I personally don't like them, but thats something the manufacturers have gone to in some instances it seems.

 

[davemoore]

Re: Tired of Jury-Rigging! / Bad New Prop?

Update:

Took the boat out all week camping... seems as though the Rubex hub may have seated itself in the prop because the wobble is almost completely gone. With the Rubex (rubber) hub, it is much smoother shifting into gear, and less vibration - everything Solas claimed in their videos. Also, the 17P 4-blade made a HUGE difference in hole-shot and getting on plane quickly, and I noticed that I don't have to trim near as much to get to that "sweet spot" - plus the response to a quick throttle-up is way faster and the stability in turns is much greater than before... I did however lose top end, just as everyone said I would.

One weird thing happened though - when idling (5 mph) in the no-wake area, there seems to be a LOT MORE slop in the steering. Is that due to the 4-blade vs. 3-blade? Couldn't figure that one out.

To Wingedwheel: I had a neighbor (long-time boat nut) look at the old prop too, and he agreed it was missing the plastic/rubber hub. The adapter that was on there was not aluminum - it was a hard metal, not sure what. I'm just grateful that it worked okay all this time.

Overall, I'm quite glad I made the switch to the 4-blade and lower pitch, and that I chose the Rubex hub system. It does exactly what I wanted it to do.

 

[steelespike]

Re: Tired of Jury-Rigging! / Bad New Prop?

"Slop in the steering" doesn't really go with a 4 blade.
No wake control is generally better.Perhaps you were over correcting your steering based on that from your old 3 blade.??

 

[mommicked]

Re: Tired of Jury-Rigging! / Bad New Prop?

My new Rubex alum.4 blade.YamaF90 came with an apparently high quality stainless thrust washer and a bronze aft spacer.it has a stainless washer to line up the factory castle nut w the hole in shaft.(new prop didnt come w cstl nut)the washer does not fit the threads so i hand centered it under the nut while tightening.also the thrust washer is a slightly larger diam. than the yamaha alum. 3 blade washer.It would seem an exhaust restriction but the motor seems to run better w this washer/prop.And the splines inside the hub are only on the back half or so of the hub. I guess its grease storage? seems like it should be the full length of the hub or else it puts more stress on the end of the shaft!I tried again to get it off the hub w the blocks and the (bounce on top method),i weigh 205, its on the hub for keeps! i have no wobble or vibration though at all.much smoother than the old slightly worn prop.cant wait to run the boat again soon!OH and my boat steers much better at all speeds w th 4 blade,18 jon boat.

 

[davemoore]

Re: Tired of Jury-Rigging! / Bad New Prop?

Interesting... well - let me add this...

How much steering control in the no wake zone do you think I'd lose if I had to grind 1/2" off the anode to get the prop to clear? :redface:

I figured when I was doing it that it was a negligible amount... could that be contributing to the slop? Seriously - it was like 1/2" or less...

Other than that, I can't think of ANY REASON why it would seem sloppier... in every other aspect, it performs so much better.

 

[1kruzer1]

Re: Tired of Jury-Rigging! / Bad New Prop?

Interesting... well - let me add this...

How much steering control in the no wake zone do you think I'd lose if I had to grind 1/2" off the anode to get the prop to clear? :redface:

I figured when I was doing it that it was a negligible amount... could that be contributing to the slop? Seriously - it was like 1/2" or less...

Other than that, I can't think of ANY REASON why it would seem sloppier... in every other aspect, it performs so much better.

From everything you describe, especially having to grind the trim tab for clearance, and if you for sure have the correct hub specified for your out drive, it sounds like you may not have the hub fully seated in the prop. That would account for the initial wobble and the lack of clearance. I found the last quarter to third of an inch of travel to fully seat the hub into the prop to be very snug and impossible to do by hand. In fact, it took a pretty strong turn of the wrench to get it to fully seat. I'm beginning to believe this is what's causing most of the problems some folks are experiencing with the Rubex hub. Another possibility might still be the old thrust washer. The prop shaft where the washer sits is tapered, and so is the mating center of the washer. Manufacturers can control the exact position of the washer on the shaft by adjusting the diameter of the center hole by a few thousndths of an inch. Even though the old washer is the same thickness as the new one, it may not be sitting in the correct position on the shaft for the new Solas prop. With all the 'rigging" of the old prop it may not even be the correct washer at all.

I'd suggest removing the new prop and verifying the hub is completely seated, and also do what it takes (shop visit?) to get the old thrust washer off the propshaft so you can install the new, correct Solas washer with the Solas prop. It'd be pretty risky to use any flame heat, such as a propane torch, so close to the shaft seal, but you CAN use gumfreeze. Use a hair dryer or a heat gun on low heat to gently but thoroughly warm the propshaft and washer, then use the gum freeze to quickly cool just the shaft, avoiding the washer. warm the whole thing again and this time use the gumfreeze only on the washer, avoiding the shaft. Repeat this cycle a few times and you may be able to get the washer to release from the shaft. Good luck!