1987 Johnson 88 special is jerking every few seconds

[TrueGrit]

I use my boat every weekend, weather permitting! My 88 special Johnson outboard will jerk & pick up speed, then slow back down to what i was cruising every few seconds in nuetral & idle speeds, at high speeds it's smooth sailing. It will also sputter as if it wants to stall out when in nuetral/idle speeds, so i to try to squeeze the gas ball and it will stall out. I changed all four spark plugs, emptied the water/fuel filter seperater and it was full of something like gas or water? My next step is to run all the gas out and get fresh gas and do a sea foam gas treatment. What else should I be looking for to stop the jerking? Please help the Red fish are calling my name on the flats!

 

[Daviet]

Re: 1987 Johnson 88 special is jerking every few seconds

Use a timing light to check each plug wire to see if you are loosing spark on a cylinder at idle. If the spark is OK, you might neede to do some carb work.

 

[TrueGrit]

Re: 1987 Johnson 88 special is jerking every few seconds

Use a timing light to check each plug wire to see if you are loosing spark on a cylinder at idle. If the spark is OK, you might neede to do some carb work.

Thanks for your reply! I just had the Johnson outboard rebuilt in July '11, with that said would the carbs need to be cleaned so soon? I will check the plug wires but they all still look new.

 

[Daviet]

Re: 1987 Johnson 88 special is jerking every few seconds

Always possiable to move some trash through the fuel line into a rebuilt carb and cause problems.

 

[TrueGrit]

Re: 1987 Johnson 88 special is jerking every few seconds

Always possiable to move some trash through the fuel line into a rebuilt carb and cause problems.

Thanks for your help! It was the right, upper powercoil that went out! It also had one bad Spark plug wire!