60 hp throttle up problem

[hobbysville]

I have a 1990-1991 60 hp johbson that when i throttle up it bogs down until the boat start to come up to plane then it will take off like nothing is wrong. If I need to throttle up when loading the boat and the boat is on the trailer it immediatly cuts off. I have soaked the carbs, and inspected the bowls and floats. the only other variable is I eliminated the oil resovoir and plugged the oil line.
Can anyone give me direction?
thanks

 

[jtexas]

Re: 60 hp throttle up problem

starboard side, under the flywheel, the throttle linkage is connected to the timer base, which advances the spark timing as the throttle is pushed forward. Engine off, observe the timer base as a helper advances the throttle (rotate the flywheel clockwise as it shifts into forward, to mesh the gears). The timer base should start moving just before the throttle plates start to open, and move smoothly through it's whole range of motion without sticking.

 

[ob]

Re: 60 hp throttle up problem

Assuming it's a 1990/1991 engine,there are idle or slow speed mix adjustment screws on the starboard side of each carburetor.Lightly seat "clockwise" all three of them one at a time and back them off counter clockwise 3 1/4 turn.Reason for seating them clockwise first is to know where each are currently set at for reference.

Next ,with the throttle lever in the neutral position,note whether the throttle cam roller is "exactly"aligned on center with the scribe line of the fiber throttle cam.and "just touching." All three carb flaps at this setting should be fully closed.There is a lock screw that can be loosened and retightened to perform this critical adjustment.

Once these settings have been attained,with engine not running,shift into forward gear while spinning the prop and advance throttle to its wide open position.Note that each carburetor flap opens to their fully horizontal position.If one or more don't ,there are lock screws on each carburetor linkage plate that can be loosened and retightened to perform this procedure.Once completed always then operate the throttle lever back to neutral to insure each are still closing fully.Fine adjustment may be necessary.

Then ,give her a rip in the water and see if your flat spot is gone.You may even find that 3 1/2 or slightly more turns of each idle mix screw is necessary to richen up the low end mix to eleiminate the throttle up flat spot.Keep a screw driver aboard with you for fine tuning .

 

[mcallan]

Re: 60 hp throttle up problem

I just did a 1900 60hp today same problem, timer base was a little out of spec according to omc's voltage/resistance readings. Replaced timer base with new and problem is gone. I also set carb low speeds at 2-1/4 turns out from lightly seated, 3 turns and runs way to fat. Mike

 

[hobbysville]

Re: 60 hp throttle up problem

First THANK YOU for your advice. But I went to the original owner and found that it is actually a 1988 Johnson outboard. If this changes things please advise and I'm sorry for the mix up.
Thanks Danny

 

[rickdb1boat]

Re: 60 hp throttle up problem

Same situation. Check the linkage as OB suggested and let us know what you find...Also, you might try pushing in on the key switch (Primer) and see if that helps. If so, you've still got crud in the carbs...

 

[jtexas]

Re: 60 hp throttle up problem

I bleeve the '88 has fixed jets, no adjustment screws...otherwise all the same.