[Beerguy]

I bought a 20ft. Campbell recently. It has an LS-6 .30 over. 830 holley, single plain manifold and roller rockers. Has a Casale 500C with 22% od gears, spinning a 13/11 3 blade prop.

Had it out today and ran it for about an hour, from Windsor launch ramp down to Copper Canyon, by the time I had got back by Crazy Horse, I had used up 1/2 tank of fuel. My tanks are 30 gal each.

I was only running it at about 2600 rpm for most of the time.

Any advise as to changes needed to make this alittle more fuel friendly?

We will be using the boat for basic cruising around the lake.

Thanks,
Larry

 

[palhal]

Larry---Keep the diameter of the prop the same but run more pitch.

 

[Beerguy]

Larry---Keep the diameter of the prop the same but run more pitch.

Go to a 14 or 15 pitch?, so run a 13/14, I can buy a 12/15 in town, should I try that one?

Thanks,
Larry

 

[Lucky]

That seems like allot of over drive - what is your max rpm ?

 

[Beerguy]

That seems like allot of over drive - what is your max rpm ?

4600 rpm, the boat came with these gears.

 

[Beerguy]

Larry---Keep the diameter of the prop the same but run more pitch.

Gary from Willmington Prop is bringing me out a 13/13 to try next week. Great guy, met him and his wife on one of our neighborhood walks.

 

[palhal]

Anything above 12" dia. is ok. You have a heavy boat.

 

[JWM]

PALHAL Working with a propeller is a good idea but I think you need to check all your engine systems.
First check the tune up of your engine. Timing is going to add some milage if it's not correct. Next check the spark plugs! Do they need to be changed? You can work with the spark plug gap to add some milage. What ignition system do you have?? This could add to your fuel issue. Next thing is the 830 carb on a .030 454 (461). Why so big? You can't use 830CFM of air at 4600 rpm. Step down the carb size and create more torque to push that heavy boat you have!!!
This is what I would do if I wanted better fuel consumption.

JW

 

[sleekcrafter]

Blown or wrong PV in carb?

 

[Beerguy]

PALHAL Working with a propeller is a good idea but I think you need to check all your engine systems.
First check the tune up of your engine. Timing is going to add some milage if it's not correct. Next check the spark plugs! Do they need to be changed? You can work with the spark plug gap to add some milage. What ignition system do you have?? This could add to your fuel issue. Next thing is the 830 carb on a .030 454 (461). Why so big? You can't use 830CFM of air at 4600 rpm. Step down the carb size and create more torque to push that heavy boat you have!!!
This is what I would do if I wanted better fuel consumption.

JW

Thank you for your advice. Plugs are new, gaped properly, plugs have a nice choc brown to them. Ignition is a Mercury Thunderbolt system. Timing is set correctly, carb was rebuilt and re jetted, 7 lbs. of fuel pressure, all this done about three weeks ago by Huston Marine in Havasu.(long time Campbell mechanic). Motor runs fantastic, so not sure about the tune-up being the problem. I will re-check the timing and the gap on the plugs.
What advice do you have as to what prop size you would recommend.

Thank you

 

[MAXIMUS]

Thank you for your advice. Plugs are new, gaped properly, plugs have a nice choc brown to them. Ignition is a Mercury Thunderbolt system. Timing is set correctly, carb was rebuilt and re jetted, 7 lbs. of fuel pressure, all this done about three weeks ago by Huston Marine in Havasu.(long time Campbell mechanic). Motor runs fantastic, so not sure about the tune-up being the problem. I will re-check the timing and the gap on the plugs.
What advice do you have as to what prop size you would recommend.

Thank you

Larry Jim has a real nice 4 blade somewhere... It might be the wrong rotation however?

 

[CampbellCarl]

Maxi
Don't you have a 3 blade you want to get rid of? I heard Whiskers didn't like it!
C