z300 cruising speed/ best fuel economy
 

Hi all. I'm finally at the lake and yes I brought the stupid blackberry with me. I'll throw it in the lake once I find out some information.
I remember reading in one of the review articles found on this site about a test done on this boat ( z300 with a 502 bravo 1) I have tryed to open the pdf file bit this crackberry won't read the file because its to large. Has someone read this article or has the same same boat, that could give me the magic rpm I should be at when cruising the lake here in british columbia canada? Also what prop they had on the test boat?
I think it was around 3000 rpm for this motor as it is for other boats in the 30 foot range.

Love this site and all the pics and help I have received in the past. Thbaks to all those who keep it going! Saw two other original mariahs on the shuswaps today. Love seeing the mariahs. Still designed way ahead of their time.

Thanks for any help!

Re: z300 cruising speed/ best fuel economy
 

According to a good friend of mine who has lived on a large lake and owned and been around boats, both power and sail, his entire life: The most economical cruising speed for a planing-type-hulled boat is a bit over that speed at which you're just planed-out. (Which makes sense.) This is going to vary based on water conditions and load. Our '94 182 Barchetta with 4.3L Mercruiser V6 and Alpha 1 Gen. II outdrive and High-5 stainless prop is just planed-out at around 2700 RPM. She really likes 3000 RPM :). On smoother water, when we can trim a bit, we'll run about 27-28 MPH by the boat's speedo at that RPM, with 2-3 people in the boat. At 2700-2800 RPM, where she's just planed-out, the occasional bigger wave will slow her down just enough to have her start falling off plane.

Had her up to 35 MPH by her speedo at about 3300 RPM (the most I'm allowed to go in the 1st 10 hours of her new engine), yesterday, on smooth water with the drive up about 25%. Boy, was that fun! :D Can't wait for the 10-hour mark, when I can start hitting it a bit harder.

Jim

Re: z300 cruising speed/ best fuel economy
 

Thanks SemiJim,

The boat planes out around 2700-2800 rpm with positive trim tabs and the leg trimmed down. Once I decrease trim on all parts, the motor likes to sit at 3000 rpm and 31.4 gps speed. This seems to make sense also, like you said.