Fuel flow meter

journey on · Posted: Tue Aug 27, 2013 8:15 pm Post subject:

I installed a Navman fuel flow meter on Journey On. It has a turbine/paddlewheel type sensor, which died on me a couple of years ago. I finally blew a stream of air through the turbine and loand behold, it came to life.

Here's what that unit taught me. First, when we're cruising and running about 10-14 knts, I'm getting about 2 mpg. It depends on 2 things: sea state and how much Judy has packed into the boat, over neither of which do I have any control. Neither speed or trim seem to matter as long as we're up on plane. If everything is right, we're up to 2.5 mpg, which is a 25% increase. When we're going a hull speed (~6-7 knts,) we're getting 4-5 knts. Actually, that's probably a little above hull speed, since at 5 knts we're getting ~6mpg. So after a while, you just ignore it, since there's not much you can do, given the circumstances.

However, it does keep track of your fuel usage and does it with remarkable accuracy. I appreciate this.

The Honda 150 is fuel injected and has a 2 stage fuel pressure system. Nevertheless the device chugs merrily along.

Boris

BRAZO · Posted: Tue Aug 27, 2013 9:56 pm Post subject:

We have a Honda digital speedometer which has the mpg and gph readings. 99% of the time I put the speed of the boat at the speed that burns 1 gph - usually around 5 to 6kts. I wouldn't run the boat without a fuel meter - its not the money for the fuel but the inconvenience of having to find and go to the fuel dock.

Mike_J · Posted: Wed Aug 28, 2013 12:19 am Post subject:

I am waiting for confirmation, but it looks like the L50s have a NMEA output that will connect to the existing network of my HDS8 (using a Navico engine interface cable (000-0120-37) and provide a bunch of info including fuel rate. If this works, then it is the most cost effective option and does not require an additional paddle wheel device. Sounds promising but I have contacted Lowrance directly to confirm that things should work.