Logo
FULL SITE MENU

Dead zone and auto-acceleration on 1998 Johnson 2 stroke

C

Comjak

New member
Hello,

I have a J50TSLECC built in 1997 (1998 model year) which runs to an original OMC throttle control box.

After the forward click on the throttle (1 past neutral), there is a significant dead zone where no acceleration happens. At about 10 oclock on the throttle, I start to get acceleration. I was told it might be a rusted throttle cable so I swapped it out yesterday with a new one and I still have this issue. Looking inside the throttle box though, it looks like the cutout on the throttle wheel for the actual cable to ride in is cut in a way that makes me thing that this dead zone is intended?

In any case, once I start acceleration, sometimes the motor will continue to accelerate even when I stop pushing the throttle any more forward. Backing off on the throttle can help it maintain speed. This issue also works when decelerating as well.

Any ideas to fix both these issues? Or mainly the acceleration issue? I'm not sure what else to do short of dropping it off at a service center.

Thanks!
 
Something in the throttle linkage sounds like it is sticking. Do this disconnect the shift linkage from the motor DO NOT have the motor running. Now have somebody run the throttle forward while you are watching the linkages move. Make sure all your linkages are moving smoothly and not lagging behind. The dead spot is normal because you cannot have the motor revving up while it is shifting. Your dead spot may be worse than normal I am not there.
 
The dead zone is after the initial dead spot to the forward neutral click. So it goes neutral, move forward to forward neutral, then a dead zone with no acceleration until like 10 oclock when it starts accelerating. I will try to see if the linkages move freely.
 
racerone said:
Are you turning the propeller when operating this control box with motor not running ??
Click to expand...

Not turning the propeller. Am I supposed to?

@flyingscott Yes first boat. I haven't had the time to go out to the garage and work on it so I just pulled up video from last year.
 
It is best to be turning the propeller when shifting this particular motor.-----Less chance to damage cables and control box !!-----And do not overthink the operation of the controls / linkages on your first motor !
 
Last edited:
Interesting. I guess the extra dead zone isn't the most problematic. I still need to diagnose the self acceleration as that's more of a safety concern.
 
There is nothing wrong with your boat. Your auto-acceleration is normal you are not driving a car. What is happening is this: When throttle is applied the boat does not instantly get up to speed it takes a little bit. So the motor will keep accelerating until it matches the throttle setting. Or think of it like this you are driving a car uphill so you have to give it more gas to maintain speed. When you get to the top and it flattens out you have to let off the gas or it will keep accelerating to match the throttle position.
 
Back
Top