Volvo penta 5.0l GXI...high fuel burn

[nical]

Hello

We recently purchased a 06 Four Winns 318 Vista.
It is equipped with twin 5.0L GXI-F coupled with 1.95 DPS drives and F4 props
It?s performance characteristics are as follows:
Time to plane: approx 45 sec
@3000 rpm speed is 25 mph
@3600 rpm speed is 29 mph
@WOT rpm is 4300 and 36 mph
Fuel consumption is 129 gal for 78 miles operating from 2000-3600 rpmThe boat initially had full fuel (170 gal) and water (35 gal). Two adults and 2 kids, groceries and drinks for 5 days.

I am very disappointed with its performance and am looking for some help.

Would you have any performance data for this boat with these engines?
Could you recommend some things to try?
Does the boat have the right propellers? What would you recommend?
What are your thoughts on four bladed props?
How can I improve performance and specially fuel consumption

tx

 

[NoExcuses]

Re: Volvo penta 5.0l GXI...high fuel burn

Manufacturers performance data for your model is here:

http://www.fourwinns.com/upload/Documents/Catalogs/2006/FastFacts_2006.pdf

Your consumption does sound high considering Four Winns shows 3000 RPM = 26 MPH = 14 GPH which would be 42 gallons for your 78 miles.

45 second to plane also seems high.

You might try posing your question on the iFourWinns site for more feedback: iFourWinns

The props are correct according to Four Winns spec sheet.

You might want to look into paint from your fuel pump assembly fouling your fuel system which may hamper performance, your engines have the pumps that are prone to this. Although, your numbers don't look very far off from the Four Winns performance data. You can search these forums for paint and fuel pumps.

 

[nical]

Re: Volvo penta 5.0l GXI...high fuel burn

Hello NoExcuses

Tx for your lead. After doing some research on fuel issues I found that Volvo has a TSB
http://www.marinepartsexpress.com/VP_Service_Bulletins/156%20%20%20%20%20%20%20%20%20%20PB%20%20%20P-23-7%20%20%20N03%20%20V01%20%20%20%20%20%20%20Fuel%20Pressure%20%20Regulator.pdf
regarding the fuel regulator. It has you removing the filter on the reg and replacing it will an E clip. When I first measured the high fuel pressure it was more than 100 psi(gage limit), after removing the filter, the pressure was at 55 psi. The engines now start without any black smoke, time to plane is 15 sec and WOT 4700.
BTW, I fully dissembled both pumps and both were clean, no paint chips.
The volvo fuel pump is made by Carter/Federal Mogul
Product Information - Vapor Separator Fuel Pump
Low pressure pump pn 3422109B
High pressure pump pn 2822119A
The fuel regulator is a standard chevy reg for 5.0l MPI