Throttle cable adjustment 7.4, 1989

I have looked up how to adjust the play in the cable and they say do it at the engine. The engine adjustment available is too short. Can you adjust it at the helm? and do cables stretch over time and need replacing.

Are you saying that the throttle plate does not fully open or does it not close?

To answer your question specifically....there isn't a lot of tension on either the throttle or shift cables. There is more tension on the steering cables. As a result...they can corrode if water finds its way into the cable which happens if the plastic covering loses integrity. Short of corrosion, the length of the wire cable doesn't change in a material way.

What I have seen is that owners replace their carbs over time and the new carb has a different throttle plate bracket that affects the full motion of the throttle plate. If you disconnect the throttle cable, you can rotate the throttle plate by hand and mark the full open position with a scratch awl or a nail on the side of the carb. Then set the throttle level at it's lowest position which fully extends the cable (also, the throttle control should move freely without binding). The position of the cable end connector should align (vertically and horizontally) with a throttle plate hole within 1/8" or so. If does not, that would raise my concern that the geometry is off. There is no adjustment at the throttle control so it needs to be adjusted at the engine end.

If you have replacement carbs.....they generally have multiple holes at different heights to try. I had one case where none of the holes worked and we had to drill the throttle plate bracket to get the geometry/open/close correct.

If you have original carbs....I would look at the throttle cable bracket to ensure it isn't bent or loose.

Hope that helps.

Thanks for getting back with a response
Cables are original to boat. They do not bind or look corroded. It is the low speed that is the problem. The slack is 3/4" of free play from off throttling up. If I bring the leaver back slowly engine will idle at 1000 RPM if I bring it back quickly I can get it down to 600RPM. The boat has upper and lower helm. The lower helm is fine it is the upper helm that has the free play. We mostly 99% use the upper helm.

That helps. The upper helm cables are longer than the lower helm and as a result have more friction inside them. If I understand you correctly the cable does not move to the idle position if you pull it back slowly. If you pull it back quickly....it behaves normally. What I would do is to put a light throttle spring on the throttle plate to help bring it back to idle. You want a light spring so that you don't overcompensate for the throttle levers assembly. That should solve the problem.

The throttle plate itself on the carb has a spring on the throttle shaft....its possible that the spring has lost its resiliency. Also, it probably is fair to say the old grease inside the cable is adding to the friction.