[Chromaflage]

OK, sad story. Yesterday I was on the CR chasing stray URBs. On my way back to the boat lauch my motor took a dump. It's a 1971 Merc 50 hp with a pump on it. I just put a new water pump in it and replaced all fuel system components from the tank up to the pump. As I was heading back to the ramp, the motor just slowed down and died as if I backed off the throttle slowly and turned the key off. No other unusual noises or smoke or anything - was purring along like a kitten. Still turns over, so it's not ceased up. So, I'm looking for input about where I might start looking for the cause of this.

Thanks in advance.

ORS

[ 09-27-2003, 11:18 PM: Message edited by: OregonRedside ]

 

[ALLEIRBAG]

I had the same problem with my mercury 20hp. One of cylinder had really low compression caused by runing the engine with bad water pump 2 months earlier. Take it to Tom Gentry outboards 3602566351 He will take care of that for you for very reasonable rates.

 

[Grits]

This may be a long shot but if you have a gas can with a breather screw, the breather screw may have been closed. Look at your tank and if the sides are kind of sucked in that can be the problem.

 

[rustyl]

Yea, this sounds like a common symptom I see when something is messed up with the fuel lines. For me it usually is what Grits pointed out where my breather screw on the gas tank as closed and my tank is starting implode. One time I had a defective check-valve/primer-bulb, and then yesterday I had a kink in the fuel line caused by my tank resting against it (which is easy to do if you have a portable tank and are rushing to load the boat for a fishing trip).

For me it is always the case that I can reprime to get restarted, and then the engine will soon die if the root cause was not fixed.

 

[Flatfish]

Fuel? Spark? Chech all spark plugs for juice. Same with the carbs.

If it has both do a compression check.

Report back here with results.

Mark and the dog.

 

[Chromaflage]

will do flatlfish! thanks all for input. I will be checking out everything this week. I think i know why this happened and why we got no fish - my fishing partner had the gall to bring a banana on board.

what's the proper ay to do a comp check? should I pull all plugs at once or pull one at a time?

ORS

[ 09-28-2003, 10:00 AM: Message edited by: OregonRedside ]

 

[Timberdoodle]

My 850 Merc from 1974 had a similar problem. Fuel pump diaphram had not been reinstalled correctly and had a slight pinch on one edge. Engine ran okay under low fuel demand but try to put a load on it and it would bog out. Repumping the bulb temporarily alleviated the condition.
Hey, I think we can really light up the chat forum with engine trouble topics.

 

[Chromaflage]

Thanks LPH - I agree - I've also suggested a boating safety forum - in light of losing those two guys earlier this month.

ORS

 

[Grits]

I would pull one plug at a time and check to see if it has spark. Make sure you hold the electorde to something metal and then have someone bump the motor.

It really sounds like a fuel line problem to me. If you have spark, you might put a little fuel directely into the carb and the try to start it. If it starts up and dies you will have a good indication that it is probably your fuel line, tank or any filter/pump from that leads to the carb.

I would check all the low tech stuff before taking it to a mechanic.