Thoughts on speed...

TheSalt

Hi Guys...

Just a quick thought on speed....  My new (to me) 266 Fiesta Vee came equipped with a 7.4 and a Bravo 3.  After putting around the lake the past two weekends, I will make a quick observation...  This thing is SLOW.  Mind you, I am not after any kind of speed record but I had no idea my top speed would be roughly 35 mph.  Seems like I am in slowmo, at least compared to my last 21" runabout with a 350.  I could pull close to 50 mph in it.  I actually dont care too much about speed in most cases...  just wanting to make sure I am running a healthy motor at healthy speeds.  

Any thoughts on this?  Is 35 acceptable? 

Matt

Black_Diamond

Start by comparing your actual WOT when trimmed out to the rpm spec for the motor, that will tell you if you are proped right. Otherwise you need to look at fuel delivery and engine tuning.

Michael T

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aero3113

My 2001 242 Fiesta Vee does about 28-30 mph with a 260HP 5.7. I would think you are within specs but may be able to get a little more with a different prop. When was the last time your engine got a good tune up? Also how much gear and people were on it at the time?

TheSalt

Yes, I was loaded with coolers, kids and camp gear.  The engine has 330 hp and the 266 was full of gas and water.  I will pay closer to WOT RPMs.  I think I topped 5500 RPMs last week on the lake and have since read that 4800 should be max...  Does this jive?

aero3113

When you can try to go out with just yourself , no gear half fuel/water and see what you get.

aero3113

Here is a spec sheet for you. Print it out and take it with you and compare/write down what you get. You can even bring it to a prop shop and see what they recommend. http://www.perfprotech.com/blog/articles/mercruiser-74lbigv8-marine-engines-specifications

Lifes Good

My guess and the question I would have is whay is the outdrive great ratio? Start there and then tune with the proper prop for your elevation. What is your elevation? My buddy bought a boat from Utah were many boats have a higher gear ratios. When they are later sold to area that is closer to sea level the props must be changed lowering rpm significantly while increasing major speed.

gslpro

Matt, just curios, what are you using for your speedometer?  I am guessing a gps of some sorts.  

TheSalt

I am at a higher elevation...  the lake we play in is probably 5500".  I did use a GPS for the speedometer.

Gear ratio seems logical too...  My last boat, at Lake Havasu ran a good 6 mph faster than our higher elevation Utah lakes.

All good tips!  Thanks.

gslpro said:

Matt, just curios, what are you using for your speedometer?  I am guessing a gps of some sorts.