Motor killed

[Walli1]

Coming off the river last night going wide open my motor killed, hit the key and started right back up went another 1/4 mile or so and it died again, hit the key and it started right up again, slowly give it gas and when I got to about 1/2 throttle it started to die so I drove it the next three miles or so at half throttle and put the boat on the trailer, today I hooked up the water and hit the key and it seemed to run just fine , checked the fuel filter it was fine, I'm stumped! HELP!!

[croixflats]

One cause could be a fuel pump going out. Be sure to get it cheked out before next outing.

If it is a fuel pump it can run to lean and burn a piston up. I learned this the hard way.

[Walli1]

Took the boat out after going over everything I possibly could and it ran just fine I havn't a clue what the heck that was all about!

[boatfixer]

Possibly an air leak in the fuel line somewhere.

[Walli1]

Yeah I was thinking that but the ball stays hard, boat has a in floor tank, line looks good, think I'd be best off replacing it with new one?

[eurolarva]

What kind of motor? Older mercs with the black stators did just what you mentioned. They were recalled and replaced with a red stator.

[Walli1]

1992 60 mariner 3 cylinder

[pinkfloyd4ever]

This might be just a crazy coincidence and I had a post on here a few weeks back about my 98 Yamaha. The exact same scenario as you described. My step dad is an old school mechanic, told me dump the gas out, use it in the lawnmower, put 2 gallons gas in and one full can of sea foam, get it out on a lake and burn it up. So I did that, burned up that gas in about 30 minutes, refilled the tank and now it runs like the day I got it put on.

[Walli1]

still motor issues, I rebuilt the fuel pump, put in new spark plugs, fuel filter, new gas line, took out the on board tank, drained the gas, did a compression test that checked out fine, the motor seems to run good except goes noticeably slower, any clues, help

[chickeywing]

What kind of spark plugs? My 25 horse will only run on NGK. It won't plane out on Champions.

TC

[Surface Tension]

When an outboard quits while running down the lake, resist the temptation of starting it back up and taking off again. You should first check to see if its overheating. That could be from a bad impeller or lack of injector oil from one reason or another. You'll get a warning low oil warning buzz but that won't tell you if theres and obstruction or disconnected oil line.

In this case it sounds like the outboard was originally starving for gas. Primer bulb being hard eliminated the fuel pump and gas line. Improper(low)fuel level in the carbs bowl would be my guess. Still you have to make sure it wasn't an overheating problem. You can try this. Remove the fuel line from the carb. Using the primer bulb push gas though the line and into a container. Look for any debris. Connect that line back up. Drain the carbs bowl. The float will drop leaving the inlet valve wide open. Flush that out using the primer bulb again.

Seems to run fine now but "noticeable slower". This could be related to the original problem but for the heck of it, pull the spark plugs and look for a wet plug. Could be you cracked the insulation or its just bad, or the plug wire wasn't seated.

[boatfixer]

ST makes a good point about the temp of the engine.

I always like to determine whether or not it is an ignition, fuel or compression, etc., before throwing a bunch a parts into it. Some simple ways to help narrow it down. Try tapping the choke or if you have someone to help, using a squirt can with gas in it, manually inject gas into the front of the carbs while its acting up. If the engine picks up, sounds like you have a fuel problem. Another thing to try (and I suggest this one alot for a reason) Hook up a timing light and watch the light when it acts up. Neither of these suggestions will always work or wont pinpoint the problem but may help get you going in the right direction.

I've always liked using NGK plugs in mercs as well.

[Walli1]

NGK is what I put in there, thats what was there before, I'm sure its not over heating as the water stream really sprays out good, did however change the oil I've been running for years from quick silver to amsoil can't imagine that makes any difference