High rpms in idle

[basbalj288]

85 horsepower Johnson 1976. The high speed jets in the carbs were damaged so I replaced just the bottom bowls where the high speed jets are located from an exact pair of used carbs from a scrap motor. Now when I turn the engine on the idle rpms are way too high. So high that I am unable to shift into gear. I have adjusted the throttle cables so that the throttle arm is as far back as it will go. Could this be an issue with the high speed jets being stuck open? Or any other suggestions. Planned on being on the water in a couple hours.

 

[emdsapmgr]

Re: High rpms in idle

May just be an adjustment. When at idle, the carb butterflys must be completely closed. Those carbs have special, dedicated idle passages in the carbs-used only when the butterflys are completely closed. At this point, the mains are not functioning. If, during your removal and re-install, the carb sync and link gets off-one or both of the butterflys may be slightly ajar. That's a problem. You need to pull the airbox cover off and have a look. Best to take the throttle cable off while making an carb adjustments. Once you know they are closed, the idle adjustment is made through timing-not by any carb adjustment. The sync and link procedure, while not rocket science, is a detailed important procedure. It's well outlined in the factory service manual.

 

[basbalj288]

Re: High rpms in idle

That worked the other day! The bottom carb was just slightly open when in idle so I loosened the spring loaded screw and it went back to the closed position and started much nicer. In fact, it starts now at a little too low of RPM so I need to adjust the throttle cables better I'm assuming. I read the manual but I'm having too much play in the cables so that when I lift up the Warm up level to the Start position, it doesn't really advance the throttle at all.... Any suggestions on how to tighten that up so the lever will be more responsive