Plastic Prop

[Nasher]

Been looking for a spare prop on the cheap for my Suzi 200EFI for a while, and have now picked up off the dreaded ebay a Piranha 4 blade 14" x 22" with a spare blade. It was advertised for a big OMC, but I was once told by JW that the shafts etc are the same, and can confirm now that it fits a treat.

It'll be a few weeks before I get to try it out but it will be interesting to see how it compares to the Suzi stainless 3 blade 14.75" x 22" thats on there at the moment.

As it will only be a spare to get home when I run aground at priory bay again! I'm not too bothered (and it was only £37.50), but should I expect it to give similar performance?

Apart from anything else its going to be a lot lighter to carry than an Ali or stainless spare.

Nasher.

[jwalker]

I tried the Piranha props on my 150 OMC. Kinda strange. They had limited top speed and changing the pitch didn't have the expected effect on performance. It didn't make too much sense but they went back to the supplier. However, it was not long after that the corroded spark plug caps, which we both know of, began to to give problems and I've always wondered whether that was the cause of the odd behaviour.

Having said that, the one notable thing about the props was their ability to hang on in difficult situations where my other props would loose grip. This was all pre my introduction to the Torqueshift which became the only prop to have.

[jwalker]

Originally Posted by Nasher

.. It was advertised for a big OMC, but I was once told by JW that the shafts etc are the same, and can confirm now that it fits a treat.

Nasher, are you sure? I told you that the OMC & Merc props have the same spline as the Suzi but the taper is in a different position and they would contact the gearcase and you need a short spacer to keep them back a little.

[Nasher]

Jw, hi.

The Piranha I've brought has a built in bronze/Brass thrust washer at the back with the taper machined into it, although it came with a seperate thrust washer as well. The machining on this seperate washer does not match the back face of the prop in any way however ,and is exactly the same as the old spare thrust washer I have from when I had my old Johnson VRO. It must have just been a spacer for the OMC, and being quite large does obstruct the exhaust ports in the prop.

With the seperate washer, there is not enough thread showing to get the main nut on and a split pin.

Without the seperate washer it all lines up as if it were made for the engine, even the back of the prop sits just inside the gearcase with a couple of mm clearance on diameter, exactly the same as my existing Suzi prop.
I've tightened it up onto the old bottom end for my engine I have in the garage. This unit has a huge lump missing out the side of the exhaust chamber so I can even see the clearance on the bearing housing etc.

Perhaps I should start investigating part numbers.

Nasher

[jwalker]

That's interesting, Nasher. The first Piranha prop I got was one of the first imports and the clearances were a bit tight on the Merc motor I had at that time. The prop fitted neatly but when the shaft was pushed home into the housing to remove the endfloat, the prop just made contact with the retaining nut within the housing. I had to skim a wee bit off the front face of the hub.

The difference in the position of the Suzi taper is only about 5mm. I wonder whether they are now making the hub a neat fit on the Suzi and it'll still be ok 5mm further out on the OMC/Merc shafts. It would certainly overcome the problem I described above and also make the prop universal.

Anyway, I'm sure it will be excellent as a backup and it could even become your main prop.

Interestingly, Piranha are making a duoprop for Volvo but they're not allowed to sell it directly. I guess it's a Volvo commission. Volvo must be happy with the performance to have taken the bother.

Let us know how you get on.