OMC 5.7 won't idle

[hemidoc]

Re: OMC 5.7 won't idle

Thanks Bond-o

There was no high speed miss until I changed the points, condensor, cap and rotor. The boat ran great before that, it just did not idle

I had that problem it was the points adjustment. Got tired of messing with the points and went electronic with a kit. For the Idle I also had thisi problem Try adjusting your carb for the idle before overhauling it. Adjust the idle mixture(two screws bottom front of carb) adjust idle speed and cold idle(the screw was missing from mine)

 

[chris0061]

Re: OMC 5.7 won't idle

A great way to tell something here is when its warm and idling spray starting fluid on the side of the carbs where the gaskets are, could be your vacume leake is from a dryied out gasket. When you spray the fluid and it goes to normal idle you know were your problems are.

 

[79Rude115]

Re: OMC 5.7 won't idle

Thanks for all of the info, I am going to work on it this weekend and let you know how it comes out. The one problem I have is that it only seems to have the problem when under a load so I have to take it to the lake for each test, I am not able to tell if there is a problem when running on muffs.

 

[79Rude115]

Re: OMC 5.7 won't idle

Ok I think I got it fixed. The problem was two of the spark plug wires were switched (#3 & #6). The idle is still a little rough, it seems a little camy for a 260 hp motor. I think my points gap is good but I guess time will tell. The manual is dead wrong on the location of the #1 connection, it shows it to be the first one in front of the cap screw on the right side however it is actually the second connection in front of the cap screw.

As a side note I have been very impressed with NAPA's ability to cross the OMC and Sierra parts to their own brand. I have been able to get all my parts at very good prices and they usually can have them on the same day if you call before lunch. I got a really nice deal on a great set of plug wires by looking up the sierra part number and having them cross reference that instead of the OMC number.

 

[79Rude115]

Re: OMC 5.7 won't idle

She is running ok now but still wont idle for very long, starts to miss after idleing for 15-20 secods when warm and eventually dies. I am not able to get it started without opening the throttle a good bit. Going to test for vacuum leaks next - if that does not work I guess it is time to rebuild the carb. Will update with results after next steps.