Fuel Flow on Merc 5.7 260hp Carb

[Mlkman]

Last week I was out cruising and took notice to my flow scan showing a 20 gallon per hour burn rate on my port engine. The boat usually runs about 12 gallons max at the same RPM's and speed. Then I noticed that my fuel gauge was rather low which leads me to believe that the engine was burning excess fuel.<br /><br />Wouldn't you see a trail of gas from the exhaust in the water?<br /><br />Does anyone have a recommendation on things to check? I think that the carb needs so TLC.<br /><br />Thanks for the help.

 

[Bondo]

Re: Fuel Flow on Merc 5.7 260hp Carb

"Wouldn't you see a trail of gas from the exhaust in the water?" <br />Not Nessesarily.........<br />It's late in the Season... How Nasty is your boat Bottom getting ??? A Little Bottom-Growth will do This....<br />How long has it been since your last Tune-Up ?????<br />If you think the Carb is acting up, it Probably IS..... Plugs ?? Cap,+ Rotor ?? PlugWires ?? Compression Test ??<br /><br />What's the starboard motor doing ????

 

[crazy charlie]

Re: Fuel Flow on Merc 5.7 260hp Carb

The wrong prop will do the same thing.Also if you have accumulated carry on items on the boat throughout the season,the weight has increased.How much water is in the water tank and is your holding tank full.This can all amount to a lot of weight.Charlie

 

[Mlkman]

Re: Fuel Flow on Merc 5.7 260hp Carb

Thanks guys for the insight. There is no added weight. The boat is pretty much the same as the beginning of the season weight wise. The bottom could have some extra growth but the starboard engine is not drawing as much fuel as the port. I spoke to one of my crew this weekend and he remembered the exhaust looking darker on the port side. Running rich?<br /><br />I also noticed this weekend that the rpm's while motoring around 1000rpms would fluctuate on the port tach and the starboard would remain the same.<br /><br />Thanks again.<br />MLKMAN