1969 55 evinrude sstarving for gas

[perry1]

1969 55 evinrude starts and idles fine, but wont fully accelerate , seems like its starving for gas, can someone help.thanks

 

[jtexas]

Re: 1969 55 evinrude sstarving for gas

Start with compression check, post your results.
Spark tester (couple bucks at auto parts store), set the gap at 7/16", look for a bright blue spark.
Had the motor long and have you recently done any maintenance on it?
Recently added any weight to the boat?
Does the fuel line hold pressure?
When you accelerate, is it coughing, does it die, or just bogging/won't get up on plane? Have you tried pumping the primer bulb during acceleration? If that helps, its an indication of a weak fuel pump.
If everything else checks out, sounds like time for a carb rebuild.

 

[JB]

Re: 1969 55 evinrude sstarving for gas

That engine can start and idle "fine" on 2 cylinders, Perry.

First find out if all cylinders are making power. Disable each spark plug, in turn, at idle. If the idle speed drops that cylinder is making power. If there is no change or if the idle speed picks up a bit that cylinder is not making power.

If you have a dead cylinder, spray some fuel premix into the carb for that cylinder. If the idle picks up you have a carb problem on that cylinder. If not, the most likely suspect becomes ignition.

If you have no dead cylinder, pick up where jtexas advises.

 

[perry1]

Re: 1969 55 evinrude sstarving for gas

had the boat for three years, this is a new problem,all 3 cylinders have 100 to 110 lbs compression, the boat will idle fine and no weight has been added, when i lower the throttle lever the motor does not bog or cough , it will just not get up and plane....thanks again

 

[reload]

Re: 1969 55 evinrude sstarving for gas

Check the throttle linkage to be sure the carb is actualy opening all the way. If it is then rebuild carb

 

[jtexas]

Re: 1969 55 evinrude sstarving for gas

Check the throttle linkage to be sure the carb is actualy opening all the way. If it is then rebuild carb

yup. highly recommend the factory service manual, available at kencook.com or marineengine.com, will more than pay for itself on your first carb rebuild. let us know how it turns out.

 

[JB]

Re: 1969 55 evinrude sstarving for gas

Have you checked that all three are making power, Perry? Compression means nothing to a cylinder that has poor spark or no fuel.