Idle Surging

[brielly]

I just put the boat in the water today. It was idling fine in the driveway and was idling good at the ramp but then it just died. When I restarted it it kept on surging up and down. It would smooth out for a few seconds and then start surging again. I took it home and went through the carbs but they were perfectly clean. I'm thinking maybe this is an electrical issue? Its a 91 merc v135. Anyone have any pointers or trouble shooting techniques to get me started? Thanks

 

[Barnacle_Bill]

Re: Idle Surging

Look for a loose fuel line fitting or a crack in the line. Especially the primer bulb. And make sure the tank vent is open.

 

[brielly]

Re: Idle Surging

The lines look good and the primer bulb is new. I checked for spark on all cylinders and that seems fine as well, Although with my spark checker I can only see thats its firing and not how strong the spark is. I also checked the fuel pump and idle stabilizer but they seem to be good as well. I do have a lot of gas/oil leaking from the carbs after i shut it down but this was happening before the idle problem.