85hp rough idle

[ladano]

'92 85hp yamaha, I have completely been through the carbs and its still there. I've pulled each plug while idling with good fire at each cylinder. It runs strong throughout the rpm range. Only problem there is that it lost its prime running WOT 1 time. I squeezed the bulb about half way and it picked up again. When I say rough idle I mean its jerking with a miss. Thanx

 

[ladano]

Re: 85hp rough idle

I have a '87 70hp for parts, can the electronics be swapped for diagonsis? Any suggestions are appreciated. Thanx

 

[Ray Neudecker]

Re: 85hp rough idle

Still sounds like a fuel restriction. A leaking fuel pump can cause this also. Or a fuel line connector.

 

[deejaycee_2000]

Re: 85hp rough idle

I had the same problem with my 90hp Mercury, I replaced all the fuel filters and the problem was solved, maybe you must try replacing all your fuel filters, or use some fuel cleaning treatment from quicksilver.

 

[ladano]

Re: 85hp rough idle

I have a new inline filter, but didn't think about the one near the pump. I also was running a quicksilver ringfree (don't remember) in the 1st 2 tanks. I'll pick up another filter and diaphram. Thanx