Re: 1988 Johson SPL 88hp 4cylinder
First, idle speed needs to be adjusted with the boat in the water, it cannot be accurately done on a flushing device in your driveway. You have to verify that once your idle speed is correctly set that the idle stop screw is touching its stop boss. <br /><br />Once this is accomplished, put the boat back on the trailer or tie up to your dock, shut the engine off and adjust your throttle cable (at the motor). First disconnect the cable and remove it from its trunnion pocket (holder). Put the shifter handle into forward gear (you'll feel the detent in the shifter mechanism), then pull the handle half way back to nuetral. This removes any "lost motion" from the cable assembly. Now go back to the motor and re-connect the throttle cable and adjust the trunnion to fit back into its pocket - it should have a very slight pull on it, but not too much or your shifter will bind. Following this procedure should eliminate the overly high idle you're experiencing.<br /><br />What do you call a "minor score"?? Have you had the cylinder head off?? If so, can you catch your fingernail in the score?? If not, don't worry about it, if yes, what is each cylinders compression readings? The 90 degree cross-flows are virtually bullet-proof and have excellent idle qualities, they're noted for their trolling ability.<br /><br />-John
