fuel efficiency

[Nebrios]

Heres the situation my friends....1994 chris craft 21 foot concept cuddy.carbureted 302 high output.In my quest for lesser fuel consumption I have updated the electronic ignition and a complete tune up....plug gaps set per electronic ignition companys specs...and valves checked for lash...I noticed the spark arrestor was only 6 inches wide and 2 inches thick,seemed a lil restrictive to me. So the questions are....carbureted or fuel injected? Would a taller and wider arrestor help out? And prop....is there a formula to figure out prop size?

[E_]

depends on what you are doing.

If you don't mind taking a little while to get on plane and don't need to rev out maybe a more agressive prop to cruise along with?
I know when I went from aluminium to stainless prop and changed the pitch just slightly more agressive I got better fuel economy on my 305 Carb merc in my 21' Cuddy I had..


I think we need pics. not cause it would help you but just cause I love seeing boats especially when it is one of someone I kinda know. lol

[Nebrios]

depends on what you are doing.

If you don't mind taking a little while to get on plane and don't need to rev out maybe a more agressive prop to cruise along with?
I know when I went from aluminium to stainless prop and changed the pitch just slightly more agressive I got better fuel economy on my 305 Carb merc in my 21' Cuddy I had..


I think we need pics. not cause it would help you but just cause I love seeing boats especially when it is one of someone I kinda know. lol

Just cruising down the lake...no tubes no skis....right now I can run at 40 mph at about 3500 rpm. Id like to keep the speed but lower the rpms...obviously changing the prop would be a start. At the moment planning is not an issue....she will jump up on plane quickly...

[E_]

Hopefully someone with much more experience than me will respond as well..