Just repowered w 2003 Mercury 50hp, won't run

[mlbinseattle]

Engines need spark, fuel, and air. Are you sure you're getting fuel to the carbs? Also, how are you pumping the bulb? It should be in a vertical position while squeezing to ensure all air doesn't remain in the line. One time, I thought my bulb was hard, but there was a big air bubble that kept the gas from getting to the carb. I pulled the plugs, and those were dry. (I had just installed new plugs, so it was easy to tell.). I had to squeeze the bulb hard, and finally, the bubble went away. Cranked right up after that.

Pull your plugs, wipe those off, and try it. If it still doesn't start, pull the plugs to see if those are getting "wet". That should tell you if gas is getting sucked into the cylinders. If gas is getting in there, and you know that you have good spark, then it's either a carb or ignoring system issue. Carb may need adjustment or cleaning, or timing could be off. Anytime anything is done on the carbs or ignition system, the timing should be checked and a link and sync performed.

 

[ERock82]

I've already put 10 hrs into diagnosing this. Gonna have to surrender to the service shop

I'll get a diagnosis for $50 and fix whatever myself or have the seller fix if it's parts I need, but it might be simple enough that the shop gets it going.

 

[Bill kubiak]

To start any carb adjustment you should turn that adjusting screws in until it bottoms out lightly then turn it out 1 1/2 turns, the motor should start, adjust it on muffs or in a barrel by turning it in until the motor runs worse then count the turns as you back it out after a turn or two the motor will run better then get worse again, now turn it in about halfway between the stumbles, and then set it about a 1/4 turn out to get it slightly on the rich side, when you get the boat in the water do it again at idle, some say do it in gear and some say in neutral, I do mine in gear, when the boat is in the water but still on the trailer.

TIP Always start and warm up your motor at home before you hit the ramp, you never want to be that guy blocking the ramp an unable to start his motor. Once I have it running I get out tie to the dock while my wife or fishing pal stays with the boat while I park the trailer. if it is a long dock they move the boat to the end so someone else can come and launch behind us. It's called Ramp Etiquette

 

[ERock82]

Thanks. Just trying to rule things out:

If a motor was running great when I picked it up a few days ago, then won't start once rigged on boat, could it possibly be the carb adjustment screws?

I would think not bc I would guess that all 3 screws would have to have been messed with a lot.

I also think I could rule out stuck float needles bc it would be unlikely all 3 needles get stuck all of a sudden.

 

[jbcurt00]

Erock82
Did you see my post above:

E,
Try not to start multiple topics about the same problem. It's especially helpful to see ALL that's been done so far, even if it still won't start.

I changed the title to this topic and merged it w/ the previous topic.

Again, a bump or a BTTT post from you, will bring your topic to the top of the recent post list. The motor still doesn't run, and although you listed a long list of what you have ruled out, further help can find the previously done work and advice helpful in trying to ID what's wrong. Multiple topics make it more difficult.

I merged your carb adjustment topic into this one.

 

[ERock82]

New Update to outboard not starting: Almost figured it out.

Well, I thought I had it figured out. I have at least gotten further along in the diagnosis I think.

The last time I posted I had messed with the choke the night before with no result.


The other day I tried the choke again but in different order.

I advanced the throttle a little, then choked for about 20 seconds and it started up. I got it to start 4 times in a row. The 3rd and 4th starts were a little hesitant.

The difference with that night and the one before that didn't work was that I didn't try the advancing throttle method till the 3rd attempt. Maybe the spark plugs fouled from the first and 2nd attempts that when I tried like I did the other night, it didn't work. I had already checked plugs from fouling on a previous night and they were clean. Who knows?


Anyway, I went out again last night just to make sure it still started. (After advancing throttle I no longer needed to do that for it to start?..as it should be)

Well?It didn't want to start. It however, would only start if the throttle was advanced. It would die out if I brought it back to idle.

I tried adjusting the idle speed with no luck.

I gave up.

An hour later I was packing my tools up and decided to just try again. It starts up flawlessly in idle with no choke!!!

Does it a 2nd time.

What the heck?????!!!!!

I have that feeling it will not start again tonight. Please?.any ideas are appreciated. Thanks.