Fuel consumption not equal on 6.2s Mercs.

[jfboucher]

Hi, I have a 320 '04 with 6.2s Mercruiser and it looks like the starboard engine uses up about 10% more fuel than the port one. Also, top RPM are lower by 200rpm on the starboard side. I have also had the shafts checked for straightness and they came out perfect.

Any ideas ?

Thanks.

 

[Hampton]

All else being in good working order, your starboard prop has too much bite. Check the correct stats for your props, have them pulled and measured, then tuned to an educated guess as to how to equalize them (not the same pitch - one transmission runs in reverse and therefore has a different gear ratio).

Did you know your genny pulls off of one tank only? Make sure the numbers you have are verified, not just Smart Craft. Also, the tachs aren't perfect - verify that data.

Also, the port prop may need more bite. Check your max RPM for your motors and that of your boat with a clean bottom and well loaded up (fuel, people...).

 

[Jimmy Buoy]

Just went through a similar thing with my boat. I had the props worked, but the original problem persisted. It was however, more pronounced than last season.

It turned out to be at least one spark plug that wouldn't fire under load. Replacing the plugs cured the problem.

Sometimes it's difficult to determine if it's the engine not providing as much power as the other, or if one prop is more aggressive than the other one.:huh: