Motor Stalls

Bman · May 15, 2005, 08:34:19 PM

Ok, my motor has been stalling when I go to get on plane. Sometimes it just hesate, but it seems to be getting worse. The motor idles fine though.
It is a 1989 Mariner 90hp
Here is what I have down so far:
Change primer ball
new plugs
has fuel pressure(at least when I got it on ear muffs)

I have noticed that the primer ball has not been staying hard. I have looked for air leaks in hoses and found none.

Anyone got any ideas?

Bman

Kal-Kevin · May 15, 2005, 08:57:06 PM

did you check the carb for water I have heard of motors running fine till you start pulling more gas and then stalling or running rough. just thought it might help out!

Bman · May 16, 2005, 07:13:53 PM

Ok I don't want to sound like a fool, but how do I do that Kal-Kevin.
Bman

Way2slow · May 16, 2005, 07:59:27 PM

Make sure none of those little rubber tubes on top of the carbs are cracked or leaking. Then I would look into have the carbs rebuilt and adjusted. Mercs will do this if the low speed/idle is too lean.

Bman · May 16, 2005, 08:52:05 PM

I had carbs done last year. I wouldn't think they would go bad that quick?
Bman

Way2slow · May 17, 2005, 06:16:51 AM

It's very easy for the carbs to gum up if the boat sat very long during and they weren't drained.

Another thing I've found that will cause the problem is the timing not fully advancing. This can be caused by the plastic cover over the wires from the timer base, it gets hard and will bind it up.

Bman · May 23, 2005, 08:02:25 PM

I have checked the stator it is good and fixed air leak. Can the plugs be the cause of this, I have been using Champion? I might try the NKG they say they burn hotter.

Bman

Bassn77 · May 27, 2005, 07:18:31 PM

Hope this helps. Mine was doing the same thing, Idle fine, but wouldn't get up on the pad and plane out. Check your coil condisor's.. One of mine was cracked and was arcking off on the motor. guy fix it with some Jb weld. take it by and let some one look at them, that may be the problem.. I was like up I checked all that I could and couldn't figure it out.

Bman · May 27, 2005, 07:49:17 PM

I think that it is an air leak in fuel line connection to motor. I watched it threw the fuel filter. It takes it a couple second to build up enough gas. I would pump primer ball and then disconnect it. Motor held pressure. The primer ball when disconnected from motor will also stay hard. If new part doesn't work then it off to the shop

Bman

Skeeter1 · June 01, 2005, 10:54:01 PM

Alright brother, I have a 1987 Force 125 and I had the EXACT same deal as you. It ideled great it would get on plane great then it would hesitate and loose power.

Here's how I troubleshot it: Checked the ball, it wouldn't stay firm with the motor running at higher RPM's. I replaced the ball. The NEW ball did the same thing. Thought I might have got a bad one from the factory so I replaced it as well. The NEW NEW ball did the same thing (not the ball). Checked the feeder line inside the tank. It was clean and not clogged. Checked the fuel cap. Wasn't too tight or loose. Fuel cap was good. Bought a new gasket set for the fuel pump. Didn't make a change. Rebuilt the carbs a SECOND time. No diffrence. Pulled the stator off and looked for missing or cracked wires and or potting material. Everything looked good. I noticed that if I got on plane and backed it down to about 3200-3600 RPMs it ran better. Definently a fuel problem. I noticed that when it started to stall if I kept squeezing the ball it would pick back up. I went on Ebay and LUCKLY found a fuel pump off a much newer Force for a $1. Put the new fuel pump on and it runs like a dream now. The kits for my fuel pump only included the diaphram and gasket. It didn't include the spring crush seals. And that's what it was. They would move freely but it still wasn't enough. So all those HOURS of troubleshooting came down to a lousy $1 fuel pump I got off Ebay.

I didn't know much about outboards before this, but I'm dang near a pro now.