Rough idle

[Scott-14]

I have purchased a 1998 Proline with a 200hp. Mercury Offshore o.b. And I have noticed at idle(in neutral) it seems to be running rough. I only notice this at idle and at times it will stall. I was wondering if anyone has any ideas on the problem. It was serviced by my mechanic this spring but he said the plugs looked fine and did not change them. Or maybe a fuel issue? It has a new fuel/water seperator and new in-line fuel filter. Any ideas would be a great help. <br /><br />Thanks

 

[m_bickle]

Re: Rough idle

Sounds like a sync and Link is needed as well adjust the timing and idle while in gear. The service you got may not have included this or the person doing it did a half a$$ job.

 

[mcginleyc]

Re: Rough idle

Scott, I was wondering if this motor is carbed, efi, optimax? If it is carbed I would then ask wheather it was winterized or stored for extended periods. If your mechanic did a tune up then the link n sync should have been part of that, as well as replacing the plugs after inspection. If its not the sync n link then I would go to the carbs and look there.

 

[fishingtomatoseed]

Re: Rough idle

I have a question on the sync n link what is that?

 

[mcginleyc]

Re: Rough idle

fts, a link n sync is adjusting the idle, Wide open throttle, and the ldle speed screw to within manufacturer specs on a manual timing advance ignition. It involves using a timing light to see if the engine timing is adequate. Engine timing on a outboard refers to the posistion the crankshaft is in when the spark plug ignites the fuel/air mix inside the cylinder. If it is off the engin will not perform right and will not function as the manufacturer intended.

 

[fishingtomatoseed]

Re: Rough idle

Thank you for the explanation.

 

[boat geek]

I have the same boat and motor even same problem I rebuilt the fuel pump which was trashed and after the rebuild all is well