Mercury 60hp Bigfoot revs high at idle

[seaway81]

I have a 1999 Mercury Bigfoot 60 hp engine that revs to about 2500 rpms as soon as I fire it up. I have inspected the vacuum hoses and all seem to be okay. Where should the butterflies be positioned when in neutral at idle? as it is now, they are all opened about an 1/8 of an inch. If this is too much, how do I adjust them? Thanks for any help!

 

[Don S]

Re: Mercury 60hp Bigfoot revs high at idle

They should be completely closed at idle.
May be due for a complete sync and link if things are that far off.
Is it a 2 stroke, 4 stroke, carbed, EFI ?????

 

[Silvertip]

Re: Mercury 60hp Bigfoot revs high at idle

Has someone been messing with cable adjustments in the hopes of solving this issue????

 

[seaway81]

Re: Mercury 60hp Bigfoot revs high at idle

It is a 2 stroke engine and it was running well on the first trip out. I ran the boat for about 10 minutes and then throttled down at which time the engine died. When I restarted it, it fired back up and the rpms were up at 2500 or so. Nothing has been adjusted, all i did was take off the airbox to look at the carbs.

 

[Don S]

Re: Mercury 60hp Bigfoot revs high at idle

Look at the port side of the motor and see if it's coming all the way back to the idle stop screw, and that all the linkage is still hooked up.

 

[seaway81]

Re: Mercury 60hp Bigfoot revs high at idle

Okay, I will check that. If it is not, what is the process to adjust to get the butterflies to close completely?

 

[Don S]

Re: Mercury 60hp Bigfoot revs high at idle

Here is the sync & link instructions from the OEM service manual that eveyone should have if they want to work on their own motors.

 

[seaway81]

Re: Mercury 60hp Bigfoot revs high at idle

Thank you very much! looks like a call to the mechanic is in order as that looks to be over my head. I really appreciate your help.

Matt