GPH Readings - Sound Right?

[Bergertime]

All,

I just recently installed a fuel flow meter on my 98 OMC/Johnson 225 (running a 15x17 SS prop).  I am looking for some validation as my Garmin plotter and Lowrance flow sensor say I am burning approx. 13 gallons per hour at 29 mph (approx 4100 rpms) and close to 14gph at 30mph (approx. 4300 rpms).  I am curious as to how this matches up for those of you that have a similar rig.  If I remember correctly Marc said he is getting close to 14 gph on his rig at similar speed and rpm range.  

The one thing that is causing me pause is that I had to install the sensor just past my inline fuel filter under the cowling and it's sitting flat vs. the recommendation of a vertical position.  With the location of the VRU pump, size of sensor and fuel line configuration that type of install would have been more complicated.  Anyway, just trying to see if the horizontal location appears to be causing any meaningful degradation in gph calculations.  Below are a couple pics from yesterday.  Water conditions were very calm with just me in the boat, light gear load and 3/4 tank (approx 90 gallons) of fuel.  Any info would be greatly appreciated.

[flounderpounder225]

All,

I just recently installed a fuel flow meter on my 98 OMC/Johnson 225 (running a 15x17 SS prop).  I am looking for some validation as my Garmin plotter and Lowrance flow sensor say I am burning approx. 13 gallons per hour at 29 mph (approx 4100 rpms) and close to 14gph at 30mph (approx. 4300 rpms).  I am curious as to how this matches up for those of you that have a similar rig.  If I remember correctly Marc said he is getting close to 14 gph on his explorer at a similar speed and rpm range.  

The one thing that is causing me pause is that I had to install the sensor just past my inline fuel filter under the cowling and it's sitting flat vs. the recommendation of a vertical position.  With the location of the VRU pump, size of sensor and fuel line configuration that type of install would have been more complicated.  Anyway, just trying to see if the horizontal location appears to be causing any meaningful degradation in gph calculations.  Below are a couple pics from yesterday.  Water conditions were very calm with just me in the boat, light gear load and 3/4 tank (approx 90 gallons) of fuel.  Any info would be greatly appreciated.

Those burn numbers look correct, I am right at that (close anyway) with my 250 HPDI.. maybe slight less on slick water, light load, but the HPDI is assumed to get slightly better GPH than a Carb'd similar motor.  I thinnk your good to go.

[Capt. Bob]

I'm a gallon less (12) at 4100, 28/29 mph but........

My Flow Scan is analog so that's an approximation and on a Yamaha 200. Your numbers seem almost identical to my old 96 Rude 200, still.....

You need to use the "fill it up" method a few times in order to gain a high confidence level in the gauge but it seems to be pretty close out of the box.

Good luck.

[Bergertime]

Thanks guys!  The confirmation is much appreciated!

B

[Capt. Bob]

Yep,
You'll enjoy this little upgrade. It gives a really good feeling if you've traveled a long way and know you have plenty of fuel left.

No more bouncy gauge. :bounce:

[wingtime]

Those numbers sound pretty close to mine.  My Explorer with the same motor and prop size shows about 14-15 gph range at 4200 RPM at 30 MPH on my Floscan.  Considering my boat is heavier, has a hard top, bottom paint, and a cabin those numbers are pretty close.

[TheKid]

DId you install this up in the cowling after the inline filter?

A better place is after the fuel water seperator where you can get it in the vertical orientation.

...or maybe I misunderstood your post.