Gas milage

[biggraypig]

How much do you suck?
I know we don't buy jet boats for gas milage, we buy them for the fun factor.
Well I had a crazy idea and thought it might be fun to know the different setups you are running, and the gas milage you get out of them at different speeds?

[sleekcrafter]

this might be easier to figure Gallons Per Hour, Engine RPM and speed vary so much, from boat to boat.

[raisinL]

A 460 bbf, 4 barrel carb, 4 people in it not really good. Then add 6 in my family and bringin some freinds we just say I need to run alot of toys. Running 2 waverunner and a speedster {the kids wakeboard from}and my jet a day on the lake can run up to 200 bucks with booze add another hundo. But hey I'm not complaining the returnables net me some coin back. lol

[SmokinLowriderSS]

Gets you to teh marina = good mileage.
Stops 1/2 mile short of the gas pump = bad mileage.
We burn about 3 1/2 hrs skiing or tubing on 20 gallons, 2 hrs+ or so just "power-druising".
454, moderately built, Performer RPM Air Gap, Lightning Headers, 700 CFM Holley double pumper, Aggressor B (berk A) impeller in a Berk F.
Don't ask how fast the needle drops when she's making 5-grand, or the nitrous is on.:eek: :eek: :eek:

[Cas]

This is from a post I made last year when I made a change to the motor-
Here are the numbers from Shasta using the new vacuum sec carb as opposed to the double pumper. Both carbs were built by Bigs Performance using all the specs from my engine.
2005- 80 degrees, mostly overcast with a little rain. BBC, 30 over, Team G single plane intake manifold, Bigs built Holley 750 dp, Bassett thru transom headers, 21 year old Berk JG/A, place diverter, 5º wedge, 12 gals gas (approx 6 gals in each tank). We were able to run for about 2 1/2 hours on 22 gals of gas. We went through about 60 gals of gas last year.
71.8 mph @ 5000 rpms
2006- about 105 degrees. BBC, 30 over, Edelbrock Air Gap dual plane intake manifold, Bigs built Holley 750 vacuum secondary with adjustable vacuum unit, Bassett thru transom headers, 22 year old Berk JG/A, place diverter, 5º wedge, 24 gals gas (both tanks full). After running for about 6 hours over 2 days I filled up with 12 gals of gas. I didn't fill up again and had another 6 or 7 hours of no wot runs, just cruising.
69.8 mph @ 5200 rpms
200 rpm gain and about triple the gas mileage!
Even though the speed was down from last year, I'm sure it's totally related to the temps and the extra weight due to carrying more gas. I don't know what the air density comparison is but I do know that with the 105º temps it's like running in higher altitude. In any case, for my set-up I've got a pretty good gain with the vs and Air Gap intake along with a whole lot better gas mileage. I'm realy happy with the results!
Oh yea, the adjustable vacuum unit...first gps run was 62.8. I turned the adjustment screw out 1/4 turn and got the 69.8. I didn't go any further with it as I needed to get back the the beach for some float time with family and a bunch of friends.
This past winter the pump was freshened up with a A/B impeller so we'll see what happens to mph and fuel consumption with the vs carb.

[Ken F]

I'm unable to answer your question because I don't even want to know the answer myself.
Ken F

[ck7684]

Good question...mine actually doesnt do too badly, perhaps because it's only a 16 footer?? I'll fill the 16 gal tank and bring along 10 more gallons to keep at the cabin. If I do a lot of boating over a weekend then I will use the extra, but I dont always dip into it...

[pw_Tony]

With my 20' Daycruiser I get bout 2-3 miles per gallon. I run 18 miles from fishers to Piccacho and it uses 8-10 gallons. I run a 4-barrel on a pretty damn mild 460 bbf. Just bout dual 660's double pumpers off ebay for the blower.... gas I'm not gonna figure it anymore

[centerhill condor]

the condor has "AA" and gives reasonable fuel economy. But that is relative. The condor tops out at about 55 mph 4200 rpm so we're not winding out the engine.

[W.O.T]

depending on how i drive id say 1-2 mpg with a 468BBC and dual 750 demon carbs.

[jbone]

502 with 850 dp and an A impeller in a heavy 21 ft open bow. I get about 2 miles to the gallon, maybe a touch more. That is cruising at 4,000 rpm, with the occasional 5200 rpm and a rooster tail for fun.
Lets say it's not cheap!:mad:
J

[SB]

Biesmeyer 21, stock 460, Aggressor A. We ski and tube all day on under 20 gallons.
Which I suppose is about 2-3 mpg.
Looking at it another way; it takes 1 gallon to make 12 hp for an hour.
My jet at skiing speeds, hits 3000-3200 rpm, which is about 100-120 hp, which is about 10 gallons/hr., cruising at 30-35 mph.
Wide open, a big block can use 30-50 gallons an hour.

[jtmarten]

I get 2-2.5 mpg with my 23' Daycruiser; mild 454 with a Holley vac 750 cruising 3200-3500 (secondaries not open), Berk JC-A/place diverter, 2 25gal tanks. Big, heavy boat so I'm not complaining! The price of gas just gives more reason to anchor off and throw down a few cold ones!

[El Prosecutor]

Mild 455, AA American Turbine impeller, 4200 rpm max,
heavy 19' boat,
4 or 5 passengers including one or two tubing or wakeboarding 1/2 the time,
and a few "speed" (i.e 56 mph) and roost runs for good measure,
= we average about 4.5 gallons per hour.
That aint that bad when you consider that it is almost exactly what I get with my '90 Yamaha Superjet (one rider standup jet ski).

[biggraypig]

It's lookin like the (boat/gas : man/beer) ratio is almost equal. Give or take a few.
Thanks for the posts. Isn't this fun.

[AZLAW]

Launch your boat up river float approx. 8-10 mph for free, drink a 30 pack start boat and drive back to were you launched at crusing speed cost about $30 for gas and beer. Bring 3 friends have one by the beer and two split gas and YOU can enjoy driving your boat for free! F$#@ high gas prices drop a nuke!

[biggraypig]

Nice plan. I like it.