Logo
FULL SITE MENU

50 multiple problems

D

dtwolcot2

Member
"Hi, I have a 1999 5.0 with an

"Hi, I have a 1999 5.0 with an alpha one with a few problems. One of the problems was a dieseling problem but I think I may have that fixed. The throttle was not returning all the way back to idle after moving the throttle resulting in a high idle. The other problem I have not figured out so much, but am leaning towards a carb rebuild. When I mash the throttle the motor wants to die and when I return it imediatley to idle it comes back. If i ease on the throttle everything seems fine and this happens with the engine loaded or unloaded. Also during this the motor seemed to backfire? There was popping coming from the exhaust during throttling up. These symptom started after I put ethanol treatment in gas cause I thought there may have been water in tank. Since then I emptied the fuel filter and found no water in gas. But I did notice with the engine at idle and flame arrester off it looked like moisture was building up on the throttle plates inside the carb. Is this water or does gas do this too? The last problem I have is I started to find large amounts of metal on the magnet from the drive gear. The magnet was completely covered. I also just had the gimbal bearing replaced. was something done wrong in its replacement that would cause this? Thanks and sorry for the many problems and long post."
 
A carb rebuild may be needed b

A carb rebuild may be needed but it sounds like just replacing the accellerator pump will cure the carb problem. The moisture is condensing due to the difference in the fuel and air temperatures; not an issue. Are you getting what looks like pencil sharpener shavings on the magenet or chuncks of metal? Gimbal bearing not connected with the metal on the magnet.
 
"Thanks Guy, The magnet has wh

"Thanks Guy, The magnet has what you described as pencil sharpener shavings on it, but seems to accumilate fast as in the last 5-6 hrs of use. Whats the going rate to do a carb rebuild and replace the accelerator pump? Thanks"
 
"well if your having an accel

"well if your having an accel pump issue, may as well have entire carb rebuilt, usually about $100 +- kit price some include some are extra. ..

Definately check the outdrive oil level and pull the bottom plug to see if there is any fluid or water in there."
 
"I didnt see any water in the

"I didnt see any water in the gear lube. I drained it into a clear container and didnt see any water even after a day to see if any water would seperate to the top. One thing I did notice though, was the drive lube was a transparent yellow-brown color when I put it in, and when I drained it, it was kinda a solid dark green color. Is the color change normal?"
 
"if it was the merc special ge

"if it was the merc special gear oil it will mix with the water and never separate. Your carb problem may be fixed with a carb rebuild.

The dieseling may be improper technique in operation of a carbed motor.

Pump the throttle 2-3 times in neutral leave 1/3 of the way down and start motor.

When warmed uo 3-4 minutes then it's time to pull away from the dock and easy on the throttle.

Slowly down with the throttle till you you reach your desired rpm, usually 2/3 of wot.

Then when you come off plane slowly, and allow the motor to idle in neutral 3-4 minutes before shutting down.

Carb rebuild, means new gaskets anyway demands a kit no matter what if you open it up, usually there is a new needle seat, needle accel. pump and ball bearing, depending on the carb.

The pieces on the magnet, hmmmmmm sounds like normal wear, if you post a pic of it maybe we can tell a little better.

No big chunks correct?

And as always if you suspect water in the drive a pressure test. And some say a vacuum test also.

One other thing there is a filter in the fitting that enters the carb, it clean?

Some have a filter in the fuel pump if manual.

You could check the fuel pump pressure 4-7 psi no less.

And finally there is a anti-syphin valve sort of a one way valve at the fitting that enters the tank. Screw off and blow thru it it it should not be dirty and maybe gunked up, also when you pull the valve should have a screen on the bottom of the fuel pickup tube. It dirty?

Also vent to tank clear no critters, spiders in there blocking the vent?

All good with the filters i am leaning to improper technique concerning operation of a carbed motor.

Good luck."
 
"I didnt use merc lube, I beli

"I didnt use merc lube, I believe it was Quicksilver. As far as operating a carbed motor, I know all these things you mentioned and practice it. Also the anti-syphin valve works and pickup is clean."
 
"if your referring to turn key

"if your referring to turn key starting then no. As far as pulling the risers, I dont know. Boat was given to me by a friend and boat was maitained properly, but before given to had sat for a year and a half. I pulled the spark plugs today and all of them were black. I know they are supposed to be a light tan brown color. Compression was 150 psi on all cylinders. Figured while I was taking them out might as well check compression. I've pulled the carb to do a rebuild. Does the timing need to be checked? With black plugs am I still looking at possible accel pump problem? Rebuilding carb either way. Thanks"
 
"Your original post described

"Your original post described moisture on the throttle plates - potential indicator of a few minor problems.

If the carb is right and the engine tuned correctly, all the fuel at idle should go thru the idle ports. These are below the throttle plates. so nothing should accumulate on the plates at idle.

Could be float is getting wet, needle is leaking or the idle circuit(s) is clogged. Rebuild is good thing to do.

Change the float while you have it apart. Check the new needle and seat as well. Make sure the idle circuits are clean. Whe you get it running again, make sure it is thoroughly warmmed up before setting the idle adjustments."
 
Back
Top