Nissan 5 hp rev's at high RPM - won't idle - help

[rookiecap]

I just bought a used 1998 5 hp Nissan outboard that starts great, but runs at an extremely high rpm. I have tried to adjust the idle but cannot get it to alter RPM's. It is so high it vibrates the motor and I don't want to put it in in Forward or reverse for fear of damaging the gears. My question is, how do I adjust the RPM's lower?

 

[TOHATSU GURU]

Re: Nissan 5 hp rev's at high RPM - won't idle - help

You have to determine what the problem is before you do anything else. IE Where is the engine stuck in the WOT position? Is it the throttle grip or something in the carburetor.

 

[rookiecap]

Re: Nissan 5 hp rev's at high RPM - won't idle - help

Okay, mixed brand new fuel and spent the day adjusting the idle screw cap and the throttle screw cap as both were all the way in when I got it. Got the motor to almost idle but can't get it to idle independently without adjusting throttle every 5 seconds. The carborator is now soaking in carb cleaner and I am hoping that solves the problem. The motor is no longer racing and it is not vibrating more than expected.... Any other suggestions?

 

[TOHATSU GURU]

Re: Nissan 5 hp rev's at high RPM - won't idle - help

Service manual and start from the beginning.