Why So Slow????

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FishBaja
Posts: 2
Joined: Mon Jun 22, 2009 11:07 am
Region: West-coast
Boat Year: 2006
Boat Mfg: Glacier Bay
Boat Model: 2680

Why So Slow????

Postby FishBaja » Mon Jul 17, 2017 7:18 pm

Help Guys:

My 2006 2665 Center Console is running 10 MPH slower than factory and magazine tests show.

Dual Honda 150's, 900 hours, 5900 RPM,
Top Speed is 30 MPH, 25 MPH at 5,000 RPM, on Garmin GPS.

I Have 15.25 x 17 C/R Props. Test Boat has 14.75 x 17 props.

All filters new. One mechanic says Bottom Paint is causing it.

Others disagree.

Boat has Dual "Dolfin" type cavitation plate extensions.

Boat set-up to factory standards... 1st. hole, etc. Not Loaded with weight.

Taking cavitation plate extensions off for next trial. Does Bottom Paint really cause 10 MPH difference? or ???

Thanks,

Jeff

koastal
Posts: 18
Joined: Sat Aug 15, 2015 5:19 am
Boat Year: 2000
Boat Mfg: Glacier Bay
Boat Model: 2640

Re: Why So Slow????

Postby koastal » Mon Jul 17, 2017 8:47 pm

Sounds like a dirty bottom. Doesnt take much to knock of a lot of speed.

My 2640 swings 15 x 15 enertia props on 135 Merc 4 strokes and does 32mph at 5000 rpm

Yours with bigger pitch / more power / more rpm should be considerably faster - gear ratio dependant.

You are making the rpm so if props are in good shape it will be either bottom or excess weight ( lots of it)

Mine has bottom paint also

FishBaja
Posts: 2
Joined: Mon Jun 22, 2009 11:07 am
Region: West-coast
Boat Year: 2006
Boat Mfg: Glacier Bay
Boat Model: 2680

Re: Why So Slow????

Postby FishBaja » Tue Jul 18, 2017 9:21 pm

Boat has not been slipped in many years. Paint is like mild rough sand paper.

Boat has (2) Dolphin-type cavitation plates.

They will come off and I will see...

Jeff

koastal
Posts: 18
Joined: Sat Aug 15, 2015 5:19 am
Boat Year: 2000
Boat Mfg: Glacier Bay
Boat Model: 2640

Re: Why So Slow????

Postby koastal » Sat Jul 29, 2017 4:57 am

Permatrims are an integral part of rectifying GB,s questionable down sea perfomance.
I wouldnt take them of, problem lies elsewhere imo

GameTime
Posts: 3
Joined: Fri Jun 01, 2012 7:05 am
Region: Atlantic
Boat Year: 2004
Boat Mfg: Glacier Bay
Boat Model: 260 Canyon Runner

Re: Why So Slow????

Postby GameTime » Thu Oct 05, 2017 9:12 am

Jeff - I have a 2004 260 with twin Yamaha 150 4strokes and it cruises fully loaded for fishing at 4500 rpms right at 30MPH with top end touching 40. My boat has the 240 gallon capacity so it doesn't quite reach the test numbers. I have the doel fins on mine and you will want to leave them on as they create the trim needed to properly steer and trim the boat. These are not meant to be condescending but here is what I would check:
1 - make sure you speed measuring instrument is accurate - compare it to your smart phone speed app and make sure you are looking at MPH vs Knots even though that is small difference
2 - make sure you props have not been altered in any way from factory pitch
3- make sure you are not carrying a hull full of water (speaking from experience)

I am not sure what prop pitch I am running but will check, I know mine have a cup in them for a little more speed. I believe I read somewhere bottom paint could cut 2-3 mph off your speed, you can probably find that somewhere on this forum. Hope you get it figure out - Byron


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