Grady 305 Performance

[Hoghunter]

Re: Grady 305 Performance ???

All I can add to my previous post is that for my boat the 17" blades are the bomb. I hit the recommended WOT, have better hole shots and get better fuel economy.

 

[Tuna Man]

Re: Grady 305 Performance ???

I am well aware that we are talking about an Express and not a Marlin, but I thought this thread may act as a reference.
viewtopic.php?f=3&t=14837

In the 305 Express performance tests I have read, they are a little slower than the marlin with the same power. I always assumed the Express was a little heavier and left it at that. I suggest you have some serious growth on the bottom of that hull. Two weeks ago on a cold (30 degree air, 50 degree water) run back to the dock as the sun was setting, my boat topped out at 5800rpm and 40.1 knots with a very light load (50 gallons fuel and not much gear as we were inshore fishing) and a smooth water. This is with F250 engines and the Powertech 19" props. I would guess the 19" SWII props would have spun a little higher and maybe propelled the boat a little faster.

Please let us know what you learn, we may all learn something as well.

 

[OSEAD]

Re: Grady 305 Performance ???

Guys I agree the bottom is likely the major culprit. I am going to follow Hoghunters results and try 17pitch with a clean bottom in the spring. I just pulled my sons 17 whaler and with his Black bottom paint the slime growth was very light. I bought the Grady this spring and the previous owner had painted it with the shark white paint. I think the light color may have something to do with the heavy slime coating i had over the season. I will be going with a dark paint this spring and hopefully that helps keep a cleaner bottom.

Scott thanks for your comments. I think the express is a little heavier and also has a more wind resistance due to the profile of the windshield and enclosure. I have the Power tech 4 blades as well.

Thanks and Happy Holidays

jim
OSEAD

 

[OSEAD]

Re: Grady 305 Performance ???

Bayrat I think the large drop is due to the fact that with 19p 3 blade props on this rig are for a light load and perfect ie no bottom paint conditions. I believe what is happening is the effect of bottom slime coat, loading the boat, and props that were already on the verge of overpitching. The fourstrokes dont have the torque of 2 strokes, its a big heavy beamy boat and so overpitching has a more drastic decline in performance.

Thants my theory, lets see in the spring if its correct :lol:

Jim