Just firing up a 50 HP mercury 500 outboard. A few Questions:?

I got it to run with ears, but it doesn't consistently run. Just every once in a while when i get lucky.

Tips to make it run more consistent?

Anything I can tune up/check to make it run in tip top shape?

The gas line /bulb is a bit goofy, and not run in the right spot. I want to re-run it through the correct

I got it to run with ears, but it doesn't consistently run. Just every once in a while when i get lucky.

Tips to make it run more consistent?

Anything I can tune up/check to make it run in tip top shape?

The gas line /bulb is a bit goofy, and not run in the right spot. I want to re-run it through the correct hole. Can i just unscrew where it hooks into the motor and re run it, screw it back in? or should i detach the hose from the metal bolt connector, and re-run the hose only (its not very far up the bolt in the first place)?

Dont want to mess anything up, very new to marine engines. Thanks, PLEASE ANSWER!

Best Answer:

hoopfella: Here's the short list on what to do on a new-to-you outboard,especially one as old as yours (from the bottom up):

-Remove the propeller, inspect for fishing line around the prop shaft, Repair or replace the prop if it's dinged bent, or missing chunks. Grease the prop shaft splines and replace the prop.
-Drain the gear oil. If the oil has any signs of water, or metal pieces, you will have to remove and disassemble the gear case, find the problem, and re-seal the gear case.
-Remove the gear case and rebuild the waterpump. Don't just replace the impeller, geta rebuild kit and replace the impeller, impeller housing, wear plate, seals and gaskets.
-Grease the pivot shaft and tilt tube, and make sure the outboard moves freely, and that there is no slop or play.
-Check the power trim, if equipped. Look for oil leaks, corroded wires and connections, worn bushings.

Now for the fun stuff- engine systems.

-Remove the spark plugs and toss them. Do a compression test- your engine should have 100 psi or better, with all cylinders within 10% of each other. Low numbers on all cylinders is probably just carbon deposits in the ring grooves. To fix this just use a de-carboning agent (Yamaha ring-free or Chevron techron are the only ones that work). Erratic readings usually indicate internal engine damage.
-Check for spark. Your ignition should make good blue spark on all cylinders with the spark tester set at 7/16".
-Inspect all wiring for frays, cracked insulation, etc.
-Replace the fuel filter and run the outboard on fresh fuel. If the outboard still runs poorly, you probably have a fuel system problem- poor pump, dirty carbs, and the list goes on. At this point, I would suggest you get a factory service manual (or make friends with a marine tech).

And save your money on SeaFoam- it's pure snake oil. It's composed of 3 items (naptha, ISO alcohol, and mineral oil) that do nothing for your engine.

Other answer:

hoopfella:
There's no magic to them — but instead of operating on pressure, like an auto fuel pump, the outboard operates on vacuum — sucking the fuel from the tank. This means that even a tiny pinhole in the line or bulb allows it to suck in air. You can reroute the line, but be sure you get it nice and tight on reassembly. My advice is to spend the $20 or so to get a new fuel line/bulb assembly, and also a small (3 gallon) fuel tank. Using the new bulb/line and tank, try it with 3/4 of a gallon of fresh gas. It will run well, probably, but if it still gives you trouble, then pour a can of sea foam into the 3/4 gallon, shake well, and let that idle through while the leg is in a barrel of water — I don't like muffs, because they are hard on the impeller if too much water pressure, and will try to overheat if not enough water pressure.

Sounds like the fuel in the tank is old — might empty it and use the old fuel for a lawn mower, or you might buy and install a fuel/water separator — modern gas has 10% alcohol, and it soaks up water.

eric:
Sea Foam saved me from a carb rebuild. And it was recommended to me by an engine mechanic. Mine was a smaller outboard (and relatively new), which may be more susceptible to ethanol-based problems, making the sea foam more effective than what may be witnessed when dealing with a larger engine. I've used ethanol-free gas ever since and the carb has been trouble-free for over two seasons now. Sea Foam is cheap. Try it.
Kenneth:
why wont the bulb pump up tight?