1985 Mercury 50 HP idle too fast

[gpfishingdude]

I picked the boat and motor up from the shop yesterday and got it on the water. It started and ran good. The only thing I didn't like was that it was ideling way too fast. I looked in the manual and couldn't find anything about idle speed adjustment, only idle mixture adjustment. I would think that the adjustment I'm looking for would be on the linkage just off the carburetor. I found one screw under an arm that is beside the top of the carburetors but turning it didn't slow the idle down. So I'm wondering if I have a faulty adjuster or if I'm adjusting the wrong thing to slow the idle?

 

[Bosunsmate]

Re: 1985 Mercury 50 HP idle too fast

Sometimes cables get worn and the timing wont go back to the idle stop screw.

check the timing advance arm goes back to the idle stop screw ok

 

[gpfishingdude]

Re: 1985 Mercury 50 HP idle too fast

Thanks! Bosunmate, I think I was adjusting the secondary throttle pickup crew instead of the idle speed. I just found some information in the manual about making the idle speed adjustment and I will check that cable to make sure it isn't limiting the movement.

 

[gpfishingdude]

Re: 1985 Mercury 50 HP idle too fast

I am about ready to take it back to the shop to see if they can figure out what went wrong with this fast idle. After adjusting the screw I had to push on the idle arm to get it to idle down and then when I reved the engine it went back to the fast idle again. Is there supposed to be a visible return spring on that idle arm or is it all contained inside the round housing above the idle speed screw? It just seems like it needs a return spring to hold back on it. Last year when we bought the boat it was idleing a little fast but now it is racing along.

 

[Bosunsmate]

Re: 1985 Mercury 50 HP idle too fast

If it idles down fine when its against the stop then try and adjust your cables to seat it there. If your cables a worn they will cause this and it becomes hard to get it to idle low and also make the correct wot setting. You could try a return spring but those i normally only see on motors pre 1970

 

[gpfishingdude]

Re: 1985 Mercury 50 HP idle too fast

Thanks for sticking with me on this. I was able to adjust the cable at the barrel so it looks like it will hold it against the stop now. I will give it a try and make further adjustments if need be later this morning at what my wife considers a decent hour for running an outboard. Can't believe I'm getting help all the way from New Zealand. Thanks again.