2002 johnson no full speed

[jnelslake]

I have a 2002 johnson 40 hp just put in a new vro unit it starts and runs but when i put it in gear will run ok for a few seconds than run at half power and be jerky like it wants to take off but wont

 

[abarron]

Re: 2002 johnson no full speed

Are u getting a fuel restriction? Bad bulb? Air leaks? pick up tube stopped up? Air vent open?

 

[jnelslake]

Re: 2002 johnson no full speed

I checked out all of the fuel line for restrictions everything looks good on the fuel end. when i put her in gear she takes off just about up on plain than just sits there plowing and jerking every few seconds. it is like it is getting starved for gas but i cant locate anything that is creating an obstruction in the gas line.

 

[SparkieBoat]

Re: 2002 johnson no full speed

get a spark gap tester and check spark, that motor has 2 cylinders correct?? once you have eliminated fuel it is compression or spark.

 

[SparkieBoat]

Re: 2002 johnson no full speed

also you really have not ruled out fuel yet, try a new fuel line with new connectors, this has been a very common problem. once I even had to replace the male fitting on the tank. try pumping bulb while it is messing up and see if that helps, if it does, its fuel problem if it does not, its probably spark related.