2275 ESP Speed Question

[HO250]

New 2011 2275 RCW ESP With a 250HO ETEC. Best Speed With 18P Viper Was 47MPH. 3/4 Tank Fuel Light Load 2 Adults. Little To No Trim Ran 6000 RPM Light Trim 6200 RPM, With little change in speed. Motor has only 7 hours on it. I thought it would run over 50mph. Is it possible the prop is slipping that much?? If so any ideas on a better choice of prop?? Motor mount heights did not change it at all. Any help would be great.

 

[Gastonguy]

I also have a 2011 2275 RCW esp and have a 250hp Yamaha SHO. Top speed so far with aluminum prop is 45mph. Can't remember the pitch but was hoping to hit 50mph. Perhaps with a change in pitch and possibly a SS prop, I may get there. There will be others responding soon to assist you.

 

[Boomers dad]

Hello HO250 and welcome to the forum. You will probably get more responces to your guestion if you post in the general pontoon forum. I am not an expert but I will try and help. Allthough 47 mph isn't bad I agree with you that I think you should hit 50 with that motor. The thing that looks somewhat odd to me is that you are hitting 6000 rpms with trim all the way down and 6200 with trim up alittle. I would try a differant prop. Check with a local prop shop. Some of those guys will let you try out differant props. Or you could contact the guys at Power Tech props they can be very helpfull. Also is your speed checked with GPS or speedo?

 

[LT1GMC]

I think you should probably have a bit more speed in that unit. I have a new 2574GLi ESP, which is several hundred pounds heavier, and with a 250 Pro Merc Verado, I am at 49 mph GPS with a 16" Enertia prop, spinning 6500 rpm. Yeah, I know I gotta get a bit more prop. But a toon running 50 looks pretty awesome though.

 

[HO250]

New 2011 2275 RCW ESP With a 250HO ETEC. Best Speed With 18P Viper Was 47MPH. 3/4 Tank Fuel Light Load 2 Adults. Little To No Trim Ran 6000 RPM Light Trim 6200 RPM, With little change in speed. Motor has only 7 hours on it. I thought it would run over 50mph. Is it possible the prop is slipping that much?? If so any ideas on a better choice of prop?? Motor mount heights did not change it at all. Any help would be great.

Speed was measured using GPS Speedo on the boat. Here are my calculations

A 18 Pitch Prop and 1.71 gear ratio at 5800 RRM Should run 57.8 with no slip

6% - 54.3

10% - 52

15% - 49.1

20% - 46.24

If Speedo and tach are accurate I have about 20 percent slip. Also when I say no trim I mean straight not tucked under. Somethings Wrong, However my dealer sets all the ESP Tritoons with a Viper Prop. Maybe others are not as fussy as I am.

Also LT1GMC your motor has a 1.85 Ratio. After the math you are running at about 6% slip which is just about right!!

 

[Boomers dad]

The speedos on the boat are GPS driven but not GPS.( according to TB ). From what I hear most of the speedos are off by 1 - 2 mph. So you may be closer than you think. So check your speed with a actual GPS unit then refigure your slip. If it's still high give the guys at Power Tech a call. They make all of there props right here in the USA and are very helpful.

 

[HO250]

The speedos on the boat are GPS driven but not GPS.( according to TB ). From what I hear most of the speedos are off by 1 - 2 mph. So you may be closer than you think. So check your speed with a actual GPS unit then refigure your slip. If it's still high give the guys at Power Tech a call. They make all of there props right here in the USA and are very helpful.

Thanks I did not know that. I will check it with my Garmin GPS this weekend

 

[LT1GMC]

The speedos on the boat are GPS driven but not GPS.( according to TB ). From what I hear most of the speedos are off by 1 - 2 mph. So you may be closer than you think. So check your speed with a actual GPS unit then refigure your slip. If it's still high give the guys at Power Tech a call. They make all of there props right here in the USA and are very helpful.

You could be right. My speedo is pitot tube driven, and it actually reads 1-2 mph low compared to my Garmin. That is a surprise to me, as most pitot units read high on top end. My Baja reads 85 mph when Garmin was at 76.

 

[HO250]

Bummer, Only getting the 47MPH on Garmin too. My Speedo is dead on. Still feel prop is slipping somewhat.When cruising at 2000 RPM, It takes 1 second to jump to 5000 RPM almost instantly!! and the boat speed takes a while to respond.Trimming doesnt seem to lift the front much either, but maybe thats normal on this type of boat. However it feels hooked up great at the slower RPM. and pulls hard on the hole shot!!! Running out of time this year for experiments. Think Ill try A 19p Merc REV 4 when I get a chance next summer. Thanks Everyone!!!