New Merc 300HP-V8 (4.6L)

[Vezo, Part II]

Oh My God! They let you run Circle K fuel through that infant? Haha

Best of Luck, Jim. Congratulations!!!

Vezo

[Bigshrimpin]

Congrats! I see a rev4 on the Merc. I can't wait to hear how she runs.

[jorgeinmiami]

Congrats. Boat and engine look great

[DonV]

Originally Posted by Bigshrimpin

Congrats! I see a rev4 on the Merc. I can't wait to hear how she runs.

Jim tells me with a full tank, two men 5880 rpm = 51.5 mph, with the 18 pitch 4 blade SST prop. Will be curious to see what his 30 mph rpm numbers are!

[77SceptreOB]

Originally Posted by DonV

Jim tells me with a full tank, two men 5880 rpm = 51.5 mph, with the 18 pitch 4 blade SST prop. Will be curious to see what his 30 mph rpm numbers are!

Yep. That’s correct. Those numbers were given to me by the Merc dealer guys that installed my engine. They tried 3 props and that one was the best. The other ones were a 4 Blade 21” that was too much prop, only 5275 rpm max at WOT. They also tried a 3 blade 18” but same top end mph but not as strong of a hole shot. So the 4 Blade 18” was the best of the 3 props.

I’m going out to the lake today to run the boat for myself. I’ll report back my findings

[rcnight]

Looking good Jimbo! I'd like to reserve my seat for Bahama 2021.

[77SceptreOB]

Had a great first day with the new motor today at the lake. Perfect weather day, sunny and around 70 degrees. The motor is all I was hoping for. Quiet, smooth, powerful, and fuel efficient. It starts just like a car. Turn the key and it’s on, even when cold. I’m definitely not used to that! The prop I’ve got is a Mercury Marine Rev4. 4 blade, 18” pitch. First run numbers are: This was with 2 people and 80 gallons of fuel

3500 RPMs/28 mph/7.5 GPH/3.73 mpg
3620/29/8.3/3.49
3700/30/8.6/3.45
3800/31/9.0/3.44
4000/33/10.1/3.26
4600/40/13.3/3.00
4740/41/13.7/2.99
5940/52.3/24.7/2.11 (WOT)

[Beaver]

I can only imagine how exciting that must be. Keep us posted.

[kmoose]

Very impressive fuel numbers Jim.

[77SceptreOB]

Originally Posted by kmoose

Very impressive fuel numbers Jim.

Thanks Ken. When I repowered with a new fuel efficient 4-stroke 300 HP motor my goal was 3.2 mpg cruise. My old 2-stroke Yamaha 225 was around 2.6. So I'm VERY happy with the ~ 3.4 mpg I'm seeing now at 30 mph cruise. That's a 30% improvement in fuel mileage vs. 2 stroke. Does that sound about right?