First Post - Zodiac RIB & Suzuki 140 (prop)

Mrdeli · 06 March 2006, 22:34

Firstly hello to everyone, this is my first post on this great site.

Late last year my brother and I bought a Zodiac Yachtline 5.3m RIB, complete with Suzuki DL140. We have been out on a few cold winter runs and have completed run in - we have topped out at exactly 50MPH (gps recording), which I'm pretty pleased about. The engine was revving out to aroun 6300. I'm after pulling a few extra mph if possible and will need a spare prop anyhow.

AT the moment it has a 21 inch aluminium prop on it. Should i change for a 21 inch or 22 inch (or more??) stainless prop. If so what am I likely to gain. The speed was with 2 up, 3/4 fuel.... maybe with say 5 or 6 up the revs will drop anyhow.... so maybe 21 inch prop is about right???

Is there (price apart) any downsides to a stainless steel prop, or are they better in all respects.

Thanks for any advice - my knowledge of props is limited!

Top banana · 06 March 2006, 23:05

Hi , I allso run the suzuki 140 and usually find i can squeeze a few more knotts buy trimming her to match the conditions. as far as a stainless prop goes if you hit somthing in the water the damage to your gear housing will
be far greater than with an alli prop which is designed to take more of the
shock. Just my opinon.

Alex Brown · 07 March 2006, 08:29

At 6300revs, you're 100revs over the max.... although peak power from what I remember is between 5800 and 6200revs.
If your usual number of people on board is 5 to 6, and she doesn't rev past 6200 then there's probably little point in changing the prop. However, if normally you run with 2 to 3 people on board, and are hitting 6300revs (can't be far off the limiter?) then the next prop up in size may benefit you and your engine. 50mph is pretty fast for a 5.3metre rib!!

The main thing for me with the stainless prop is that it doesn't dink quite so much as the ali prop. After a good day out, I could come back and you can see a few tiny chips on the ali prop, whereas the stainless doesn't get affected quite so much. In my case, 21" ali to 21" stainless hasn't given me any more speed, so the lack of dinks is about the only benefit to me anyway.

I think the next ali prop up with Suzuki is 23" - if you look up prop calculators here (its been discussed a fair bit before), and bung in the Suzuki specs you should get a rough idea of what you might get out of her.

-Alex