Increased WOT with same size, pitch & Blades?

[Anderson Beach Clan]

Hello, I have a 2006 Chaparral 210ssi with the 5.7 270 hp volvo and the sx drive. This is my 3rd summer with the boat and I recently purchased a replacement prop for my OEM Volvo prop. The OEM was a 4 blade, 14.25" with a 19deg pitch. I ordered the same spec prop from iboats but this one if made by Solas part # 8613-143-19(who apparently makes Volvo props for Volvo). My question is, on my first run with this new prop, my WOT went from 4900 to 5600. I immediately throttled back when I saw that. Back at the beach I double checked the pitch and size stamped on prop and I went out for one more test and sure enough it climbed right thru 4900 and kept going. I got out of it again and for the rest of the day just kept the throttle back to avoid over revving the engine. Has anyone else experienced this and if so whats going on? I re-installed my Volvo prop for this weekend and have a call in to Solas on the question. Any info would be appreciated. Thank you.

 

[45Auto]

Re: Increased WOT with same size, pitch & Blades?

Sounds like one of the props wasn't quite within specs, I would bet it was the Solas! None of the pitches on any brand prop are exact, they are within a range of the stamped pitch. They're usually a lot closer than that, though.

 

[steelespike]

Re: Increased WOT with same size, pitch & Blades?

I've seen a lot of excellent results on here with the Solas Amita 4 blade.
They seem to be very predictable.
Was the old prop a stainless?I would wonder if it may have been doctored
Cup or pitch added.Tell us about the Chaparral.Unless its a cruiser type or a real bruiser it seems to me a 19 wouldn't be enough prop.

 

[Anderson Beach Clan]

Re: Increased WOT with same size, pitch & Blades?

The Chaparral 210ssi is a 21' open bow stern drive sport boat. We use it for tubing and wakeboarding and just cruising. It has excellent hole shot and indicates right about 51mph for top speed at 4900-4950 rpm with the volvo 14.25 x 19 deg aluminum 4 blade prop. I was very happy with the results but wanted a spare prop and thought I would try the Solas. (less expensive also) The Solas prop seemed to have the exact same torque and acceleration out of the hole and my speed was coming up (45 mph) and thats when I glanced down and saw my rpm's at 5600. Weird.
hope that helps with the description. Anything else I can add just let me know.

 

[45Auto]

Re: Increased WOT with same size, pitch & Blades?

Change back to the original prop and verify the RPM just to make sure the tach isn't flaky. Did the motor sound like it was turning 5600 RPM with the Solas?

 

[Anderson Beach Clan]

Re: Increased WOT with same size, pitch & Blades?

I have the Volvo prop on and will be going out tomorrow. I will find out then if its the gauge. I honestly didn't hear the engine sound like it was over revving.
Thats what caught me off guard when I looked down at my tach. I am diligent about a good instrument scan and have never seen the tach deviate but I will definitely check it out this weekend and get back to you.

 

[Doernuth]

Re: Increased WOT with same size, pitch & Blades?

Put both props side by side on a well lit table and examine them. Do they look the same? Does one have thinner blades? Is the curve of the blades similar? Is one lighter than the other?

What is the max WOT rpm for your motor?

 

[whit71]

Re: Increased WOT with same size, pitch & Blades?

Make sure the hub kit is installed correctly.

 

[Anderson Beach Clan]

Re: Increased WOT with same size, pitch & Blades?

WOT range is 4800-5200. During my original inspection, the props look exactly alike. I have not compared the weight or thickness of the blades though. I will look at that later today.
Whit 71, This prop does not require a hub kit. Thanks for checking in.