Pontoon Boat & Deck Boat Forum

This isn't yet another thread about prop performance - it's about WEIGHT.

Yesterday I picked up my old Yamaha steel 3 blade OEM prop and another cheap aluminum 3 blade Solus prop that I bought a few years back, similar to the one I have currently mounted. The OEM was just plain more solid with thick internal gussets and weighed four times as much. That got me to wondering if I might be doing damage to the engine and drive train... There's a reason why Yamaha made the prop so heavy and solid - and I'm thinking it helps to dampen vibration and possibly gear backlash?

... and yes, I know that steel can survive a prop strike better than aluminum without fracturing, has less blade flex and is incrementally more efficient for high speed operation - so lets not "cavitate" into that discussion, thanks.

Any opinions?

Nope. Stainless just weighs much more than aluminum. I have an OEM yamaha aluminum prop that came new on my yamaha 150 years ago. Very light compared to the stainless one that I replaced it with. Motor works fine with both.

Really, your OEM steel prop weighs more then your aftermarket aluminum prop????
Weird.

"It's about weight"

Aluminum is about 1/3 the weight of steel. Everyone should weigh their prop and report back here when done.

Mine weighs 12# 7.75oz
It's an R3 14 1/4x17 SS prop

I lifted my old Yamaha 21 pitch stainless steel propeller yesterday to put it in a yard sale. I also picked up a Mercury 19 pitch aluminum prop at the same time. The stainless propeller was like picking up a chunk of lead.

Unfortunately, I had only one person out of 500+ bargain hunters even look at the props.

I used to tear up an aluminum propeller every year. I went 12 years on my first stainless propeller with hardly a scratch on it. Yes, they're worth the investment--especially on 150 hp or more.

[quote="Bamaman"]I lifted my old Yamaha 21 pitch stainless steel propeller yesterday to put it in a yard sale. I also picked up a Mercury 19 pitch aluminum prop at the same time. The stainless propeller was like picking up a chunk of lead.

Unfortunately, I had only one person out of 500+ bargain hunters even look at the props.

I used to tear up an aluminum propeller every year. I went 12 years on my first stainless propeller with hardly a scratch on it. Yes, they're worth the investment--especially on 150 hp or more.[/quote]

I think I'm going to file the leading edges of my old steel OEM prop, paint it and put it back on for comparison. I'm thinking the extra heft might help to reduce that gnarly long clunking I'm getting when shifting even if I do it rapidly. I couldn't help but notice what Yamaha has to say about their current SDS system - which wasn't available until 2010:

"The SDS system greatly reduces shifting noise and vibration. It’s what
we call “no-clunk” shifting. Ever since its fi rst day of availability, Yamaha’s
Shift Dampener System has been an instant hit. It’s so impressive, there is
a patent pending.
Using a specially-designed splined center hub and a uniquely shaped
aft spacer, the SDS system absorbs much of the force resulting from an
outboard shifting into forward or reverse gear. That means noticeably
quieter and smoother shifting."