high idling 1986, 90hp merc

[natedawghall]

I've got a 1986 90 hp merc inline 6 with distributorless ignition. It's idling at around 1200 rpm. I've checked the timing and the carbs and have looked for obvious air leaks and haven't found any. I had a professional look at it and after fiddling with the carbs and timing and replacing the trigger, he couldn't get it to idle normally either. He suggested that the flywheel was the likely culprit. What do you all think?

 

[graddy]

Re: high idling 1986, 90hp merc

Sounds like a sync and link problem. Did your tech do one.

 

[natedawghall]

Re: high idling 1986, 90hp merc

He said he did a link and synch.

 

[natedawghall]

Re: high idling 1986, 90hp merc

New developments. I started working on the carbs last night but first I wanted to crank the engine just to see how it would run after the tech worked on it. I couldn't get the bulb tight no matter how hard I pumped. I changed out the fuel line from the tank to the engine and still couldn't get the bulb tight. I changed the hose bewteen the fuel pump and the carbs to a clear one so I could look for air in the line. No matter how much I pumped, I couldn't clear the line of air. Now, I'm thinking I may have a split fuel pump diaphragm. Could this cause the excessive rpm's at idle or would this just cause it not to run at all.