CHOKED OUT?

[RONOFA]

'82 40 hp Merc outboard on 16' Fisher Marine. Took out first time this weekend and motor did not seem to sound right. Put her in the water she starts fine, pull to the dock to get wife and kid, cannot get it to start again (15-20 min). Starts, we run awhile cuts out at idle, wont start for awhile again, took cover off was going to pull fuel filter, tried it once w/ cover off, started, here is the kicker if I put the cover back on the motor would quit! I am no rocket scientist but that aint right, what at diy stuff can I do to "clean up" motor,fuel filter, plugs etc.. Any suggestions?


Sorry for the ramble very frustrated as I picked it up from the shop on friday, was under the impression they would check it all out for me!

 

[Quackrstackr]

Sounds like it needs a good old fashioned carb cleaning and possible rebuild.

 

[Andy]

Have you ever done anything to the fuel system?? Try some seafoam and see if that helps. It helped on my 7.5.

Good luck

 

[captclay]

If it will not run unless the cover is off look closely to see if maybe there is a bare wire touching the cover or maybe a fuel hose that the cover is pinching.

 

[KMixson]

Check your plug wires to see if they are touching any metal parts when you put the cover on. If they ground out it will cause the motor to die.

 

[RONOFA]

Have not done any thing to fuel system, was going to start w/ basics as far as fuel filter.
I bought the boat and it had 2 full fuel tanks and buddy told me they were only a couple of weeks? old so maybe some new/clean gas and carb clean will do the trick.
How difficult is cleaning the carb/rebuild, fairly mech inclined just never worked on boat motors so a little hesitent

 

[Fish Monger]

Not that hard to do, take you time and pay attention and you can figure it out.
Seafoam works miracles!!!!! I would definately add it to your gas to help clean the gunk out.

 

[RNcredentials]

I had the same problem last year. Turned out the float in the carb had a pin hole and was always down so your always flooding the engine. Got a carb rebuid kit & a service manual. It was fairly straight forward.

 

[Zum]

Will it run with the cover off for long periods of time?
Sounds like it's(carb) being starved of air,is there an old air filter or did anyone modify the cowling so know air can get in?

 

[Loggerhead Mike]

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Will it run with the cover off for long periods of time?
Sounds like it's(carb) being starved of air,is there an old air filter or did anyone modify the cowling so know air can get in?

x2. my boss has an old sport twin that wouldnt run w/ the cover on. turned out where'ever the air comes in threw the cover or powerhead was restricted

run that thing w/ the cover off untill its good and hot, then check your plugs. black-rich, white-lean

 

[Quackrstackr]

Even though this thread is 2 years old........

Last year, my 90 was idling rough and dragging a cylinder under load at idle speed. It would also occasionally just sort of stall for a second at speed. It was making a terrible sound at idle speed, I guess now from dragging a non-firing piston. I was just touching plug boots to see if I could feel a knock in the motor, thinking it was something bad and when I got to one of them.. it just about knocked me down. :lol: It had a hole in the side of a plug boot for some reason and was arcing on the cowling.

I fixed the boot and it runs like a top again.

I still haven't figured out why a one year old motor would have a hole in a plug boot. Must have been a void in the rubber straight from the factory.

 

[Zum]

lol...never noticed...2 years old

 

[monarch1652]

yeah them darn wires will get you pretty good. i've done it myself before. took my hand ten minutes to start feeling right again. lol