Gas econom

"Hey everyone-I have just rece

"Hey everyone-I have just recently bought a 31' chris craft catalina 310 that has mercruiser 350's in it ,my questtion is what kind of gas milage should i be getting and what would the best cruising speed be to obtain it,the boat weighs 14000 lbs dry, another question i need help with is the starboard engine seems to be buring about 25% more gas than the port side engine ,the starboard engine the one buring more gas is idleing at about 400rpm less than the port side and when cruising i have to pust the throttle a good bit higher to keep rpms the same any insight would be greatly appreciated"

"Welcome Steve:

Sounds like

"Welcome Steve:

Sounds like a real nice boat! Did the seller provide you with any service records? If they did, take a look at them for each engine and determine when the basic engine tune-up was performed and proceed from that point.

If records are not available, start with the basics to get a baseline for each engine. First, clean the flame arrestor and change the fuel filters. Check plugs, cap, rotor, spark plug wires, engine oil and change them if needed. Adjust engine timing and carb. idle to specs. If this PM does not solve your fuel consumption problem, carburetor work may be required. Good luck."

"Gas 'mileage' with tw

"Gas 'mileage' with twp 350's?... not so much.

Use your World Points Visa to pay for gas... you'll have that free trip to Paris in no time!

Sorry couldn't resist.

Like Guy said, it does sound like like a tune up is needed in that starboard engine. Does in run smoother at higher speeds... Float level too high or leaking needle valve in the carb."

also check that the choke is o

also check that the choke is opening.

Are you sure that the tachs ar

Are you sure that the tachs are correct?
The "low" idle tach may be wrong and you are running it harder thus the additional fuel burn.

I would think the boat would b

I would think the boat would be difficult to steer with one engine running faster than the other even with counter rotating props.

On a 31' 14000# boat I don

On a 31' 14000# boat I don't think that you would even notice one or two hundred RPM difference

On my 27' 7000# boat if I don't adjust/watch the throttles the tachs can be off w/o notice

"IF the choke is opening fully

"IF the choke is opening fully (you can check when it's hot), then the carb is flooding and will need a rebuild. Expect 1.0 mpg max from that setup--a fact of life.

Jeff"