linkage

Hi Everyone....I have been trying to adjust my throttle cables so I can get the boat to idle properly. It is currently idling too high(around 3000RPM in water)....I follow the instructions perfectly and it idles too high....when I try to back out the idle screw, the linkage will sometimes not...

I have a '97 Challenger 1800 with a problem in the starboard carb linkage. I though I had a faulty throttle cable at first, but then tried to move it with my hand and it took a LOT of force. It is very hard to move. The port engine is really smooth and easy to move by hand. I'm not sure what...