2012 DF250 SUZUKI 4stroke fuel consumption rate is increasing dramatically Why?

[Fishingdawg]

I started out with a fuel consumption rate of around 11 g/h @ 29 mph. Now my fuel consumption rate is 20 g/h at 29 mph. Weight (boat) hasn't changed and the Engine still will run up to 6000 rpm. What has been going down hill is my consumption rate. I recently changed the prop to see if it was an issue with the hub..no difference. Any ideas on the problem?

 

[Fishingdawg]

Since the rpm's no longer match the same speed then it would seem that the problem would be in the gauges.