Need some feedback

**Bobby** · #1 05-31-2004, 07:00 AM

I have installed a Navman 4380 on a 22' Aquasport with a 150 Yammy. took it out yesterday and calibrated. It says at 4100 rpm 30 mph in the ICW that I am using 3.78 gph. At wot it says 6.80 gph. Does this sound right??

This is a 2003 motor and boat. With 56 hours

**Crossroads** · #2 05-31-2004, 07:32 AM

No, that fuel burn seems too good to be true. I would think 10-15 gph at 4100 RPMs would be ballpark.

**Mont** · #3 05-31-2004, 08:02 AM

HP/10=GPH@WOT is a rule of thumb

**Bobby** · #4 05-31-2004, 08:27 AM

Time to get the book out and see if I forgot anything on the setup and calibration

**mcgolfer** · #5 05-31-2004, 04:57 PM

i think if you doubled your numbers for gph burned you would be pretty close...rick

**Mike in Woodlands** · #6 06-01-2004, 03:36 AM

According to some posts I read some time back on THT & the manual, it has to be mounted so the transducer inlet is directly below the exit, and then secure to the boat. If it is not vertical bubbles in the gas will cause it to read low.

I also think the reading you got is about 1/2 what you were really burning.

Mike

**Bobby** · #7 06-03-2004, 11:29 AM

Just found out the unit will not work on a EFI engine with a return line to the tank. Talked to navman they are going to return my money.