not enough power 40 hp

[seakingbob]

I have a 16' aluminum boat with a E40ELCOB 40hp Evinrude motor. The compression in the top cylinder is 140 and the bottom is 150. When I pulled the plugs the top had a champion 5825 in it and the bottom had a QL77JC4 in it. Would this make it not run to full power and why do you think they had that plug in it? I bought the boat this winter and took it out for the first time on Sunday. The boat only did about 14 mph on GPS. I would think with a 40hp it should go about 25 mph. Please give me your thoughts on this as I really need HELP!! I don't want to spend a lot of money on her. I know I have to go get plugs. Do you think I should pull the carbs and soak them.
Thanks for your help.

 

[itsaboattime]

Re: not enough power 40 hp

Before you pull the carbs off, put the correct plugs in like you said and see what happens. You might want to sea-foam the fuel too. I would also take a good look at the prop, make sure the hub isn't spun and the fins are in good condition. Does it seem to be revving out like it should? does it run smooth?

 

[Mark_VTfisherman]

Re: not enough power 40 hp

Any auto parts store like NAPA or whatever will have a guide indicating the right plug for your model year... that is a first step.

Then there are a number of things to start checking.

 

[seakingbob]

Re: not enough power 40 hp

The motor seems to revving out .The prop looks good,I need to check to make sure it's not spinning out.I just put new plugs in it.I would to change the gas before I check it again.Sould I put in a high octane gas?It was running a little ruff but it may have been from the two different plugs.

 

[Mark_VTfisherman]

Re: not enough power 40 hp

Changing out the gas may help, then add drygas (the isopropyl variety). Have you cleaned out the fuel filter and drained the carb bowl? Buy non-ethanol gasoline if you can.

High octane fuel is not going to burn better, however.

A "spun" prop hub or incorrect prop pitch should be ruled out- then you can start dealing with fuel and spark, etc.

 

[seakingbob]

Re: not enough power 40 hp

I cleaned out the fuel filter and changed the gas to my tank that I had from last fall,I did stabalize it when I winterized my other motor.I also put on my other gas line.I just started it and it revved out real nice,just need to put it in the water to see how it is under load.I'll let you know when I do that.

 

[itsaboattime]

Re: not enough power 40 hp

sounds like a spun prop to me

 

[seakingbob]

Re: not enough power 40 hp

It was the carbs,Rebuilt and runs real nice.Time to do the water pump Wish me luck