Nissan 40hp, choke goes in - engive revs way high

[surfstar]

I just got this boat with a 1997 Nissan 40hp CEF, electric start, tiller handle outboard. I changed the plugs (checked the gap) and LU oil and started it up today. After 20-30 secs of idling with the choke out, I push it in and the engine revs way up - like 3-4k RPMS at least. I had to push the choke back in to get the revs to drop. Throttle position had no effect on the RPMs, and the throttle cable seems to be working fine. <br /> Any suggestions? Is it not warmed up enough? I killed it, and started it again with the same problem, but probably ran the motor a total of 1.5 mins because of the erradic idle.

 

[DHPMARINE]

Re: Nissan 40hp, choke goes in - engive revs way high

Sounds like your choke linkage is hitting the throttle linkage.<br /><br />DHP

 

[surfstar]

Re: Nissan 40hp, choke goes in - engive revs way high

when the choke is moved in and out, the throttle cable doesn't move at all, the choke is moving a linkage that looks like it affects the air intake, but the throttle cable is not affected.

 

[Salmon Tub]

Re: Nissan 40hp, choke goes in - engive revs way high

Sounds like the pilot screws may be way lean, and to compensate, whoever tuned it, used only the idle adjustment screw to bring the idle up to spec. You should look into having a Sync and Link done on that motor (all linkages set to spec. and carb(s) synchronized to each other. How did the plugs look?

 

[surfstar]

Re: Nissan 40hp, choke goes in - engive revs way high

the plugs looked a little too oily, but other than that; normal.

 

[TOHATSU GURU]

Re: Nissan 40hp, choke goes in - engive revs way high

I think Salmon Tub is probably correct about the idle speed adjustment screw being screwed in too far. Back it all the way out until it just barely meets the linkage on the side of the carb.

 

[surfstar]

Re: Nissan 40hp, choke goes in - engive revs way high

thanks guys, I will try that and see how it goes.