Prop Novice - Suzuki 3x16x21 5R

[brucehawsker]

I have never played with a different propellor. I have an XL shaft Suzuki 150 which is splashing up water and I am a bit low in the revs I can achieve at WOT unless I am trimmed out quite a way.

A suggestion to avoid building up the transom and raising the A frame has been to try different prop or props.

This may be pissing in the wind and in reality I might have to accept the hassle of major works on transom and A frame. Bit since swapping propellor is low hassle, should I try?.

I currently have the prop supplied with the engine by the guys who re-engined her.

I am writing this new thread just in case someone who is a prop expert is on here who is different from the helpful and kind transom and engine height experts who have most generously contributed to the main current thread.

The prop is brand new Suzuki and marked 3x16x21 5R. I am no an expert so I have no idea if that is the right or wrong prop.... Not even sure I know what the numbers mean....

Any input greatly appreciated. Thanks. Bruce
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[Last Tango]

No.

There's no point in bu@@ering about with props until you get the engine setup issue sorted.
As a stating point you need to know where your max revs are coming in on a properly trimmed boat/engine and you're nowhere near that at the minute. Propellers are expensive.

[Poly]

Without reigniting the debate about your engine/transom I doubt a prop change is going to sort the big issues but will tune the final solution. The numbers mean it is a three blade prop, 16” in diameter and that in a perfect world each turn of the prop pushes the boat 21.5” forward (the pitch). And the R says it’s a normal prop (not one for counter rotating twin).

Is that the standard issue prop for the engine? It seems quite big. Is it aluminium?

The black art stuff with props though is not the pitch and diameter stuff - it’s the shapes, materials etc... in an ideal world the person who rigs your boat knows his props and has a range to pick from to get you an optimal solution. I think it’s perhaps an undersold aspect of what dealers can offer and the value it can save over messing with multiple options, rather than stack em high, sell em cheap.

[Roflhat]

You could look into hydraulic jacket plates, would make engine height and propeller tuning very straight forward. Just be careful as they put some extra stress on the transom, the less set back the less stress on the transom