Piranha propeller experiment

[Richard Lane]

If anybody wants to know about the Piranha propeller, here goes:



2002 Tracker PT 185-90 Mercury w/me, 3/4 tank gas, fishing load.



Got the 4 blade 13x20 prop in today. Excellent quality and fitment. Blades just push right in. All there is is the hub, top cap, and the blades. Installed with only the nut and washer. TOO simple! The Piranha weighs 4 lbs...same as the Mercury aluminum 3 blade.

At the lake I knew it wasn't enough pitch at idle speed. Just wasn't pushing enough water. Anyway, the boat jumps on plane but was painfully slow. I gave it full throttle and it zipped right past the 5500 rpm top speed. I let it touch 5900 rpm for a moment just to see. Obviously not near enough pitch. So....back to the drawing board!



I will exchange the 4 20 inch blades for 4 22 inch blades but this will take a while to complete through the mail. 22 inch pitch for this prop should be just about right. If not I will get 24 inch blades! Yeah, I hear you but I'm telling you this prop is funky! The factory guy at Piranah suggested the 20 inch and I didn't think it would be enough because it is only 13 inches in diameter but who am I? I listened to him and he was wrong but no big deal.



The boat handles great with the 4 blade. No blowing out in turns and no trimming in needed. No cavitating when trimmed or at the hole shot. Trims up high and lifts the bow easily (for an aluminum boat). Not as good as a Mercury Trophy 4 blade but close. Minimal steering torque which I like alot. The Piranha is smooth....REAL smooth and balanced. I like the prop and look forward to having it in the right pitch. I suspect it is still going to be slow but I am willing to give up some speed for handling.



The big question: Does it make the rattling noise in the motor? NO. Way smoother than the aluminum ....like all props should be! I fired off a nice letter to Mercury about this but that's another topic....



LT

 

[mike mantha]

youre going to want to back off in pitch if you are overreving!!Every two degrees of pitch you decrease you increase 400 rpms.The lower number in pitch the higher in rpms, just my .02 cents

 

[Scott S.]

Here's my Prop Experiment that may help some Merc Owners here with similar weight/style boats.... I have a 2002 Lund Pro Sport (sorry its not a Tracker) with a Merc 115 EFI 4 Stroke. The boat included with purchase a 21 Pitch Merc Aluminum Propeller.. The Redline Max is 6000 RPM. The stock Prop was just under 6000RPM and seemed OK at best as far as holeshot and midrange. Top end was weak in the low 40's.

Following the advice of several other Lund/Merc Owners with 115's I bought a 13 X 19 pitch Ballistic 3 Blade Stainless.. Really woke the boat up, improving holeshot, midrange and top end to 46-47 on My GPS. According to a few others they had better luck with this prop on their boat compared to Merc's Trophy Series Stainless



I then purchased a Aluminum Propeller like the one I had on my last Boat with a 60 HP Johnson looking to see if it was possible to have a good performing Aluminum... Its a Solas Alcup 3 with a Unique separate Hub You can see it at solas.com.. Once again, the solas impressed me.. You can see the obvious quality over the Merc Aluminum and it looks more like a Stainless. I have since added some weight to the boat as I have 2 more Batteries and a Trolling Motor. The SOlas turns 5900 RPM and Mid 40'with an impressive holeshot and midrange. I really feel on this and My last Boat the Solas outperformed Stainless Props.

 

[David Sailer]

Man, I sold my Ranger with a Yamaha, and got a Nitro Fish & Ski, with a Mercury to make the family happy. I'm so frustrated with this whole prop deal. It's been a long time since I made a mistake this big. The boat is ok, but the motor has sure been a dissappointment, and Mercury customer service really stinks. I now have a $425 prop I can't use, and the dealer will not take it back. Mercury or the dealers should warn customers that the 90's are not good applications for the stainless props.



Just had to vent!