Correct Prop!? Frustrating... Need Advice

[Dino2000]

Hello all,

Thank you in advance for taking your time to read and reply to this post.

I have a Sweetwater Tuscany 1880 Pontoon boat powered by a Suzuki 4 stroke 60hp (2002 DF60). The current prop is a 13.25x17; however, the boat performs very poorly. My WOT is about 4000 rpms (which I know is too low) so I have ordered a Solas 4 blade prop that is 13.25x13 in hopes of increasing my WOT rpms within normal operating range.

I realize a pontoon boat is no speed boat and I'm not trying to make it one but I am very disappointed in my top end speeds. With a load of 4 people, I'm lucky to get 13 mph. As I said, I'm not trying to make this a world class speed boat but I'm hopeful that I can get better performance considering the boat is currently propped incorrectly. I should also note that I often see boats of similar sizes with smaller engines blow by me like I'm sitting still.

Does anyone have any prop experience with an 18 foot pontoon powered by a 4 stoke 60 hp engine? If so, please provide your thoughts. It will be most helpful and appreciated.

Thanks!
- Steve

 

[Scott Danforth]

Re: Correct Prop!? Frustrating... Need Advice

how deep do you have the motor? that will affect the speed as well.

 

[Sea Rider]

Re: Correct Prop!? Frustrating... Need Advice

Check with new prop and tach max rpm at wot, best operation would be to achieve at least medium to near full rpm factory stated parameters for that engine at wot.

Happy Boating

 

[Dino2000]

Re: Correct Prop!? Frustrating... Need Advice

how deep do you have the motor? that will affect the speed as well.

Very good question and thank you for asking. Visually it appears as the engine is very low in the water which is one of the reasons I chose a 4 blade prop. My research tells me that a 4 blade bites better and could raise the stern. Hope I've made the right choice with my new prop (hasn't arrived yet)... and if not... I guess I'll have more data to make a better, more informed decision.

 

[steelespike]

Re: Correct Prop!? Frustrating... Need Advice

A 13" prop will help get a more accurate rpm and gps speed.I believe the motor is rated at 6300 max rpm.
Pretty sure the 13 won't get you there but will give a better base line.
I have a feeling there may be other issues. Be sure the throttle opens all the way.

 

[jestor68]

Re: Correct Prop!? Frustrating... Need Advice

The recommended WOT rpm range is 5300-6300 rpm.

Going from a 17 to a 13 should increase your rpm by 1100-1500 rpm, and at least get you into the lower portion of the rpm range.

 

[Dino2000]

Re: Correct Prop!? Frustrating... Need Advice

Thanks guys! The new prop arrived yesterday afternoon. It's installed and ready to go. Gonna try to get to the water today and do a WOT test to see how the new pitch and extra blade (4 blade this time vs the old 3) performs. Hopefully, WOT will put me near the range that I should be. If the prop fits, the next step is to adjust the motor height on the transom. Trying to dial this thing in.... as I said earlier.... it's frustrating when a toon of similar size, cargo and smaller engine passes me like I'm sitting still. This is no speed boat and I don't want it to be.... but.... I don't like inefficiencies.

 

[Scott Danforth]

Re: Correct Prop!? Frustrating... Need Advice

make one adjustment at a time. get the best performance from the prop, then adjust motor height.

or adjust motor height first, then prop.

 

[Outsider]

Re: Correct Prop!? Frustrating... Need Advice

or adjust motor height first, then prop.

Part swapping with props can get very expensive, much less so with motor adjustments. That's where I'd go first, check the vent plate when at cruising speed, it should be very slightly above the water flow (but getting splashed regularly) ...