Rough Start

[rustyscrew]

I have a 1993 120 hp evinrude outboard. It required a lot of work to get it running a few years ago, but compression was good and it has run like a champ since.

Lately though it starts up missing at least one cylinder. It runs rough for a bit before the others catch and then it usually runs well after that. It has been doing this for some time. Recently though it has gotten worse and it keeps stalling just after starting and then usually floods itself and wont start for awhile. I just replaced the spark plugs to see if that would help...no dice. Sounds the same. The old plugs were well worn and dirty. I also just replaced the spin on fuel filter (not the small inline one though).

Once it does catch and warms up. It tends to run well. Any thoughts?

thanks
rusty

 

[MAW31]

Re: Rough Start

whats the compression on each cylinder now?
did you verify spark at all plugs?

 

[Bifflefan]

Re: Rough Start

id look at the spark for intermitent loss, and or the carbs. when was the last rebuild on them?

 

[rustyscrew]

Re: Rough Start

These are very good questions. I haven't delved into diagnoses just yet. Short on time right now, but trying to get a sense of the best things to check first. I rebuilt the carbs 2 years ago when I was first getting the engine running. I had to rebuild all 4 of them about 3 times because they kept plugging up.

That is a good possibility. Because it runs well once it is warmed up, I have been thinking that it is not likely the electrical (spark). But I could see how dirty carbs might cause my symptoms...especially since it was a problem that slowly developed and got worse.

That might be the next step.

I don't know the compression.....

thanks! Still open for other ideas....

 

[tashasdaddy]

Re: Rough Start

check your compression. that is a vital item to know, it also gives you a reference for future problem. low compression on one cylinder can cause hard starts, and possible start to run after the motor heats up.

 

[rustyscrew]

Re: Rough Start

good to know...i have a tester, so i will check the compression. fingers crossed! I guess that makes sense. The warm cylinder and pistons would expand and create a better seal......


thanks!
rusty