New boater looking for prop advice

[DBG40]

I picked up my first ever boat last week. An SR 1750 Maxum with a 3.0 / Alpha one. It has a 21 pitch prop on it that was damaged by the previous owner, and has a few chunks knocked out of it, so it needs to be replaced. I took it out for a first run here on the CT river yesterday. It comes on plane pretty quickly, maybe 5 seconds, top speed by the stock gauges were, 42 mph at about 4600 rpm. Cruising as done at about 35 mph at about 3600 or so.
Question: I was thinking of ordering a Solas Saturn SS prop in the same 21 pitch, as the boat seems to be doing fine ( In my completely uninformed opinion) Is there any further consideration needed by going to this prop? or will it be an even swap? Thanks in advance.

 

[littlerayray]

Not an even swap if you want to even swap a 4 blade go with the mercury spitfire I started a thread about it it's your best option for an even swap here is the thread check it out http://forums.iboats.com/forum/gene...p-questions-and-topics/10014302-merc-spitfire

 

[DBG40]

Thanks for the reply. So, same 21* pitch but 1/4" less in diameter, and it's a pretty much equal performer with better hole shot? Looks like I can buy it complete for -$200, which is pretty attractive.

 

[littlerayray]

Yep I found it worth the money your results may vary though

 

[littlerayray]

Oh btw welcome to iboats

 

[DBG40]

Thanks so much for the advice, and the welcome. I've been researching your suggestion, and the reviews look solid as a rock. I found an entire install kit, shipped, for $190. A SIGNIFICANT savings over buying a stainless 3 blade, and as a bonus, I just keep the same pitch, no loss of top end, and better performance across the board. Thank you for the advice.
Dave.

 

[Rick Stephens]

That's smokin fast for a 3.0L motor. Nice. When you do your testing of the new prop take a GPS with you so you know exactly what it is giving you and at what wide open throttle RPM. It is important and may save wear and tear on an engine.

 

[DBG40]

Thanks Rick, also good advice. I thought it was a little fast as well, but the previous owner told me he had GPS'd it at the 42 mark. I'm still a little suspicious, and will definately do my own verification with a GPS when the new prop shows up. Hopefully this Thursday. It's an extremely well kept low hour boat that has been well cared for. Everything is tight and right, and being about as light as a popcorn fart may be part of it cruising along at a pretty brisk pace. The GPS will tell the truth. With that 21* prop, I can actually push it past redline at the 4,800 if I let it roll out for a little distance, nothing I'm willing to do, but it rolled up slightly over 5k by the gauge. But then, how accurate are the gauges.The engine was getting pretty excited, which made me check the RPM's and roll it back some. It could actually run that well, or it may just be the completely clueless guy running the boat. I'll let you know which it is!

 

[Rick Stephens]

Nice rig. My old 17 footer is waay too heavy for that kind of of go. I max out with a tailwind at 34. Newer lighter cleaner better designed hull and probably little or no wood in your rig. I believe in your numbers.

You might take a quality timing light with a tach built in and make sure of your builtn tach numbers. Beats overrevving.

Rick

 

[littlerayray]

Hey Rick my 3.0 runs at about 47mph now with just me in the boat and a 1/2 tank of fuel got it up to 43 mph with me the gf and about 400 lbs of camping gear the speed was measured by gps I was also trimmed out overy half

 

[Rick Stephens]

No Title

I am always impressed what these 3L will do. You guys have lots newer hulls and a lot lighter than my old fishin rig.

 

[littlerayray]

Yeah its true the newer hulls are lighter my boat is a 2012 so lots of advancements in technology and hull designs

 

[steelespike]

Hey Rick my 3.0 runs at about 47mph now with just me in the boat and a 1/2 tank of fuel got it up to 43 mph with me the gf and about 400 lbs of camping gear the speed was measured by gps I was also trimmed out overy half

I have to wonder if your speed is affected by wind or current.If we use 2.00 ratio,21" prop,10% slip @ 47 we get over 5200 rpm.

 

[DBG40]

Came in today, and I just got it swapped out. I hope to get it out on Friday.

 

[littlerayray]

I have to wonder if your speed is affected by wind or current.If we use 2.00 ratio,21" prop,10% slip @ 47 we get over 5200 rpm.

Yes that's going with the wind and the current sorry to be so misleading oh and the water Temps were in the low 60s

 

[littlerayray]

Came in today, and I just got it swapped out. I hope to get it out on Friday.

Let me know what you think of it

 

[DBG40]

OK, just got back from trying out the new prop. River was quiet flat and calm. Dropped in, warmed up, and headed down river. I started rolling the throttle on, and by the time I hit 2,500 RPM, I thought I was in a different boat. It took about 3 seconds to drop flat onto plane, and it pulled like crazy. Top end is about 5mph better that before, at 45 MPH by the GPS I took out of my truck. Best part is that it is absolutely smooth as silk. I mean a night and day difference in how it runs. Engine noise seems to be less, and there is zero buzz of vibration of any kind. Thanks for the suggestion, Littleray. A real home run there.